diff --git a/src/lib-sieve/ext-encoded-character.c b/src/lib-sieve/ext-encoded-character.c
index 3c5c7aa48ed0eb64f7893afd9aac012c85732246..d23a59a7dab3e604c59ac95cb1f5f201aece5b11 100644
--- a/src/lib-sieve/ext-encoded-character.c
+++ b/src/lib-sieve/ext-encoded-character.c
@@ -28,7 +28,7 @@ struct sieve_extension encoded_character_extension = {
 	"encoded-character", 
 	ext_encoded_character_load,
 	ext_encoded_character_validator_load, 
-	NULL, NULL, NULL, NULL,
+	NULL, NULL, NULL, NULL, NULL,
 	SIEVE_EXT_DEFINE_NO_OPERATIONS, 
 	SIEVE_EXT_DEFINE_NO_OPERANDS
 };
diff --git a/src/lib-sieve/ext-envelope.c b/src/lib-sieve/ext-envelope.c
index 4da197ff631de7acb96a6c1abc1d05d2895987c1..035288e51544a30ced9e64f636e931a77b15897b 100644
--- a/src/lib-sieve/ext-envelope.c
+++ b/src/lib-sieve/ext-envelope.c
@@ -54,7 +54,7 @@ const struct sieve_extension envelope_extension = {
 	"envelope", 
 	ext_envelope_load,
 	ext_envelope_validator_load, 
-	NULL, NULL, NULL, NULL,
+	NULL, NULL, NULL, NULL, NULL,
 	SIEVE_EXT_DEFINE_OPERATION(envelope_operation), 
 	SIEVE_EXT_DEFINE_NO_OPERANDS 
 };
diff --git a/src/lib-sieve/ext-fileinto.c b/src/lib-sieve/ext-fileinto.c
index ff8f4ecfdc5e727cbf13267286e45d989011e15f..0f88ed512984aa76aa4ca4061276223312837ffa 100644
--- a/src/lib-sieve/ext-fileinto.c
+++ b/src/lib-sieve/ext-fileinto.c
@@ -48,7 +48,7 @@ const struct sieve_extension fileinto_extension = {
 	"fileinto", 
 	ext_fileinto_load,
 	ext_fileinto_validator_load, 
-	NULL, NULL, NULL, NULL,
+	NULL, NULL, NULL, NULL, NULL,
 	SIEVE_EXT_DEFINE_OPERATION(fileinto_operation), 
 	SIEVE_EXT_DEFINE_NO_OPERANDS	
 };
diff --git a/src/lib-sieve/ext-reject.c b/src/lib-sieve/ext-reject.c
index f64c992fe5c0eb2598879aade6992d46ee6e27d1..bd044cbbc5e4c0ad3d7c3008cb4fe77392946ec2 100644
--- a/src/lib-sieve/ext-reject.c
+++ b/src/lib-sieve/ext-reject.c
@@ -54,7 +54,7 @@ struct sieve_extension reject_extension = {
 	"reject", 
 	ext_reject_load,
 	ext_reject_validator_load, 
-	NULL, NULL, NULL, NULL,
+	NULL, NULL, NULL, NULL, NULL,
 	SIEVE_EXT_DEFINE_OPERATION(reject_operation), 
 	SIEVE_EXT_DEFINE_NO_OPERANDS
 };
diff --git a/src/lib-sieve/plugins/body/ext-body.c b/src/lib-sieve/plugins/body/ext-body.c
index c64a75beb80c3b0f8a142d61d254ba8f03ecbd4a..1b6d218ac496c23c95543aa426c0947569b816f3 100644
--- a/src/lib-sieve/plugins/body/ext-body.c
+++ b/src/lib-sieve/plugins/body/ext-body.c
@@ -66,7 +66,7 @@ const struct sieve_extension body_extension = {
 	"body", 
 	ext_body_load,
 	ext_body_validator_load, 
-	NULL, NULL, NULL, NULL,
+	NULL, NULL, NULL, NULL, NULL,
 	SIEVE_EXT_DEFINE_OPERATION(body_operation), 
 	SIEVE_EXT_DEFINE_NO_OPERANDS
 };
diff --git a/src/lib-sieve/plugins/comparator-i-ascii-numeric/ext-cmp-i-ascii-numeric.c b/src/lib-sieve/plugins/comparator-i-ascii-numeric/ext-cmp-i-ascii-numeric.c
index ff70366acef770d7c29816de207405b26a46f968..5ccd18c9ef26feab1c7fd1c9d4b1ab3b2edd5a7b 100644
--- a/src/lib-sieve/plugins/comparator-i-ascii-numeric/ext-cmp-i-ascii-numeric.c
+++ b/src/lib-sieve/plugins/comparator-i-ascii-numeric/ext-cmp-i-ascii-numeric.c
@@ -33,8 +33,7 @@ const struct sieve_extension comparator_i_ascii_numeric_extension = {
 	"comparator-i;ascii-numeric", 
 	ext_cmp_i_ascii_numeric_load,
 	ext_cmp_i_ascii_numeric_validator_load,
-	NULL, 
-	NULL,
+	NULL, NULL, NULL,
 	ext_cmp_i_ascii_numeric_binary_load,  
 	NULL,
 	SIEVE_EXT_DEFINE_NO_OPERATIONS, 
diff --git a/src/lib-sieve/plugins/copy/ext-copy.c b/src/lib-sieve/plugins/copy/ext-copy.c
index ce4faa81b531808b9dbaee1f2787e72110138e52..a7e659deee8b4512f543eeb53f0887ea0d6ad5e5 100644
--- a/src/lib-sieve/plugins/copy/ext-copy.c
+++ b/src/lib-sieve/plugins/copy/ext-copy.c
@@ -35,8 +35,7 @@ const struct sieve_extension copy_extension = {
 	"copy", 
 	ext_copy_load,
 	ext_copy_validator_load, 
-	NULL, 
-	NULL,
+	NULL, NULL, NULL,
 	ext_copy_binary_load, 
 	NULL, 
 	SIEVE_EXT_DEFINE_NO_OPERATIONS,
diff --git a/src/lib-sieve/plugins/imapflags/ext-imapflags.c b/src/lib-sieve/plugins/imapflags/ext-imapflags.c
index 8dcfcd4e8da962c2c5b929bc0ffd1bf480ed0ccc..7fa2c3f6fd47cc193929c6b4cf6f3ca5a43697bc 100644
--- a/src/lib-sieve/plugins/imapflags/ext-imapflags.c
+++ b/src/lib-sieve/plugins/imapflags/ext-imapflags.c
@@ -59,7 +59,7 @@ const struct sieve_extension imapflags_extension = {
 	"imap4flags", 
 	ext_imapflags_load,
 	ext_imapflags_validator_load, 
-	NULL, 
+	NULL, NULL,
 	ext_imapflags_runtime_load, 
 	ext_imapflags_binary_load,
 	NULL,
diff --git a/src/lib-sieve/plugins/include/ext-include-common.c b/src/lib-sieve/plugins/include/ext-include-common.c
index 6b1c4ccd3892719c716ce8a10d831e9da55488c3..c32890662ba29e72b0dc6a582a318f2e3bfd4a90 100644
--- a/src/lib-sieve/plugins/include/ext-include-common.c
+++ b/src/lib-sieve/plugins/include/ext-include-common.c
@@ -167,18 +167,19 @@ static inline struct ext_include_interpreter_context *
 	return ctx;
 }
 
-void ext_include_runtime_context_init
-(const struct sieve_runtime_env *renv)
+void ext_include_interpreter_context_init
+(struct sieve_interpreter *interp)
 {
 	struct ext_include_interpreter_context *ctx = 
-		ext_include_get_interpreter_context(renv->interp);
+		ext_include_get_interpreter_context(interp);
+	struct sieve_script *script = sieve_interpreter_script(interp);
 	
 	if ( ctx == NULL ) {
 		ctx = ext_include_create_interpreter_context
-			(renv->interp, NULL, renv->script, SBIN_SYSBLOCK_MAIN_PROGRAM);
+			(interp, NULL, script, SBIN_SYSBLOCK_MAIN_PROGRAM);
 		
 		sieve_interpreter_extension_set_context
-			(renv->interp, ext_include_my_id, (void *) ctx);		
+			(interp, ext_include_my_id, (void *) ctx);		
 	}
 }
 
diff --git a/src/lib-sieve/plugins/include/ext-include-common.h b/src/lib-sieve/plugins/include/ext-include-common.h
index 35a2b80944ec5c67c40ba78600951acb39929cc8..2845de5bf6ef63840383e8c08717bae684b10e84 100644
--- a/src/lib-sieve/plugins/include/ext-include-common.h
+++ b/src/lib-sieve/plugins/include/ext-include-common.h
@@ -55,7 +55,7 @@ bool ext_include_generate_include
 
 /* Interpreter */
 
-void ext_include_runtime_context_init(const struct sieve_runtime_env *renv);
+void ext_include_interpreter_context_init(struct sieve_interpreter *interp);
 
 bool ext_include_execute_include
 	(const struct sieve_runtime_env *renv, unsigned int block_id);
diff --git a/src/lib-sieve/plugins/include/ext-include.c b/src/lib-sieve/plugins/include/ext-include.c
index d9eb0cfb33c9aa3ae7b30a6200b8bbeb0d4ba881..4592de5885666d85e1332a62e600d5a00b07d8a8 100644
--- a/src/lib-sieve/plugins/include/ext-include.c
+++ b/src/lib-sieve/plugins/include/ext-include.c
@@ -33,7 +33,7 @@ static bool ext_include_load(int ext_id);
 static bool ext_include_validator_load(struct sieve_validator *validator);
 static bool ext_include_generator_load(struct sieve_generator *gentr);
 static bool ext_include_binary_load(struct sieve_binary *sbin);
-static bool ext_include_runtime_load(const struct sieve_runtime_env *renv);
+static bool ext_include_interpreter_load(struct sieve_interpreter *interp);
 
 /* Operations */
 
@@ -54,7 +54,8 @@ const struct sieve_extension include_extension = {
 	ext_include_load,
 	ext_include_validator_load, 
 	ext_include_generator_load,
-	ext_include_runtime_load, 
+	ext_include_interpreter_load, 
+	NULL,
 	ext_include_binary_load, 
 	ext_include_binary_dump,
 	SIEVE_EXT_DEFINE_OPERATIONS(ext_include_operations),
@@ -92,10 +93,10 @@ static bool ext_include_generator_load(struct sieve_generator *gentr)
 
 /* Load extension into interpreter */
 
-static bool ext_include_runtime_load
-(const struct sieve_runtime_env *renv)
+static bool ext_include_interpreter_load
+(struct sieve_interpreter *interp)
 {
-	ext_include_runtime_context_init(renv);
+	ext_include_interpreter_context_init(interp);
 	
 	return TRUE;
 }
diff --git a/src/lib-sieve/plugins/regex/ext-regex.c b/src/lib-sieve/plugins/regex/ext-regex.c
index 28ce14413e860808c261b659def0a4c525744b30..e3fb99bce7c8b027aa3b1ad378e095d7d90fa558 100644
--- a/src/lib-sieve/plugins/regex/ext-regex.c
+++ b/src/lib-sieve/plugins/regex/ext-regex.c
@@ -51,8 +51,7 @@ const struct sieve_extension regex_extension = {
 	"regex", 
 	ext_regex_load,
 	ext_regex_validator_load,
-	NULL, 
-	NULL,
+	NULL, NULL, NULL,
 	ext_regex_binary_load,
 	NULL,  
 	SIEVE_EXT_DEFINE_NO_OPERATIONS, 
diff --git a/src/lib-sieve/plugins/relational/ext-relational.c b/src/lib-sieve/plugins/relational/ext-relational.c
index fdecfe5e9aa0cce1b896aecb0f9eac973ec8f4da..220c5e5780c29f945523cbeaa8b30c10a1c5e791 100644
--- a/src/lib-sieve/plugins/relational/ext-relational.c
+++ b/src/lib-sieve/plugins/relational/ext-relational.c
@@ -48,8 +48,7 @@ const struct sieve_extension relational_extension = {
 	"relational", 
 	ext_relational_load,
 	ext_relational_validator_load,
-	NULL, 
-	NULL,
+	NULL, NULL, NULL,
 	ext_relational_binary_load,  
 	NULL,
 	SIEVE_EXT_DEFINE_NO_OPERATIONS, 
diff --git a/src/lib-sieve/plugins/subaddress/ext-subaddress.c b/src/lib-sieve/plugins/subaddress/ext-subaddress.c
index 8a38511366a5153412ccd44970c89686dbe81605..369eb54d64c358d459d98ea5f3219bbde188d73b 100644
--- a/src/lib-sieve/plugins/subaddress/ext-subaddress.c
+++ b/src/lib-sieve/plugins/subaddress/ext-subaddress.c
@@ -41,8 +41,7 @@ const struct sieve_extension subaddress_extension = {
 	"subaddress", 
 	ext_subaddress_load,
 	ext_subaddress_validator_load,
-	NULL,
-	NULL,
+	NULL, NULL, NULL,
 	ext_subaddress_binary_load,
 	NULL,  
 	SIEVE_EXT_DEFINE_NO_OPERATIONS, 
diff --git a/src/lib-sieve/plugins/vacation/ext-vacation.c b/src/lib-sieve/plugins/vacation/ext-vacation.c
index d3f7cf64d60cc3d0df373bb04af8a98bb6e35765..dad01342ce18cad281593f4e701f51d0a01f7147 100644
--- a/src/lib-sieve/plugins/vacation/ext-vacation.c
+++ b/src/lib-sieve/plugins/vacation/ext-vacation.c
@@ -39,7 +39,7 @@ const struct sieve_extension vacation_extension = {
 	"vacation", 
 	ext_vacation_load,
 	ext_vacation_validator_load, 
-	NULL, NULL, NULL, NULL,
+	NULL, NULL, NULL, NULL, NULL,
 	SIEVE_EXT_DEFINE_OPERATION(vacation_operation),
 	SIEVE_EXT_DEFINE_NO_OPERANDS
 };
diff --git a/src/lib-sieve/plugins/variables/ext-variables.c b/src/lib-sieve/plugins/variables/ext-variables.c
index 4edfa9b6d17bc67dca6cfd3555235042954ad84e..a147e4211d54912d6234a73cf91e41f875322505 100644
--- a/src/lib-sieve/plugins/variables/ext-variables.c
+++ b/src/lib-sieve/plugins/variables/ext-variables.c
@@ -36,7 +36,7 @@
 static bool ext_variables_load(int ext_id);
 static bool ext_variables_validator_load(struct sieve_validator *validator);
 static bool ext_variables_binary_load(struct sieve_binary *sbin);
-static bool ext_variables_runtime_load(const struct sieve_runtime_env *renv);
+static bool ext_variables_interpreter_load(struct sieve_interpreter *interp);
 
 /* Commands */
 
@@ -70,7 +70,8 @@ struct sieve_extension variables_extension = {
 	ext_variables_load,
 	ext_variables_validator_load, 
 	NULL, 
-	ext_variables_runtime_load, 
+	ext_variables_interpreter_load,
+	NULL, 
 	ext_variables_binary_load,
 	NULL,
 	SIEVE_EXT_DEFINE_OPERATIONS(ext_variables_operations), 
@@ -111,10 +112,10 @@ static bool ext_variables_binary_load
 
 /* Load extension into interpreter */
 
-static bool ext_variables_runtime_load
-	(const struct sieve_runtime_env *renv)
+static bool ext_variables_interpreter_load
+	(struct sieve_interpreter *interp)
 {
-	ext_variables_interpreter_initialize(renv->interp);
+	ext_variables_interpreter_initialize(interp);
 
 	return TRUE;
 }
diff --git a/src/lib-sieve/sieve-actions.c b/src/lib-sieve/sieve-actions.c
index 844f9760d6432899efa7212f86db3013baef02bb..c5cb0f7e7e943aad251aaf76906df69b4a1c48d6 100644
--- a/src/lib-sieve/sieve-actions.c
+++ b/src/lib-sieve/sieve-actions.c
@@ -43,7 +43,7 @@ static bool seffect_binary_load(struct sieve_binary *sbin);
 const struct sieve_extension side_effects_extension = {
 	"@side-effects",
 	seffect_extension_load,
-	NULL, NULL, NULL,
+	NULL, NULL, NULL, NULL,
 	seffect_binary_load,
 	NULL,
 	SIEVE_EXT_DEFINE_NO_OPERATIONS, /* Opcode is hardcoded */
diff --git a/src/lib-sieve/sieve-address-parts.c b/src/lib-sieve/sieve-address-parts.c
index 9d72a66f413491f75c1dd86cab19b04222f6512e..e52b07a7d6e9f43f336e4836e4e5c58db89613ee 100644
--- a/src/lib-sieve/sieve-address-parts.c
+++ b/src/lib-sieve/sieve-address-parts.c
@@ -58,8 +58,7 @@ const struct sieve_extension address_part_extension = {
 	"@address-parts",
 	addrp_extension_load,
 	addrp_validator_load,
-	NULL,
-	NULL, 
+	NULL, NULL, NULL, 
 	addrp_binary_load,
 	NULL,
 	SIEVE_EXT_DEFINE_NO_OPERATIONS,
diff --git a/src/lib-sieve/sieve-comparators.c b/src/lib-sieve/sieve-comparators.c
index 198840bf32f3203b7ece9bd7c5f1c1e5a0ce4184..ae49a4399c36d46ec752d2900f9a801122756c1f 100644
--- a/src/lib-sieve/sieve-comparators.c
+++ b/src/lib-sieve/sieve-comparators.c
@@ -69,8 +69,7 @@ const struct sieve_extension comparator_extension = {
 	"@comparators",
 	cmp_extension_load,
 	cmp_validator_load,
-	NULL, 
-	NULL,
+	NULL, NULL, NULL,
 	cmp_binary_load,
 	NULL,
 	SIEVE_EXT_DEFINE_NO_OPERATIONS,
diff --git a/src/lib-sieve/sieve-extensions.c b/src/lib-sieve/sieve-extensions.c
index c349db5dcf21145cc94cc491ed36c585d4758554..f86b6e67e61933492cbb8845fbf6ba1b0d624537 100644
--- a/src/lib-sieve/sieve-extensions.c
+++ b/src/lib-sieve/sieve-extensions.c
@@ -30,14 +30,14 @@ const unsigned int sieve_preloaded_extensions_count =
 
 static const struct sieve_extension comparator_i_octet_extension = {
 	"comparator-i;octet",
-	NULL, NULL, NULL, NULL, NULL, NULL,
+	NULL, NULL, NULL, NULL, NULL, NULL, NULL,
 	SIEVE_EXT_DEFINE_NO_OPERATIONS, 
 	SIEVE_EXT_DEFINE_NO_OPERANDS
 };
 
 static const struct sieve_extension comparator_i_ascii_casemap_extension = {
 	"comparator-i;ascii-casemap",
-	NULL, NULL, NULL, NULL, NULL, NULL,
+	NULL, NULL, NULL, NULL, NULL, NULL, NULL,
 	SIEVE_EXT_DEFINE_NO_OPERATIONS, 
 	SIEVE_EXT_DEFINE_NO_OPERANDS
 };
@@ -202,8 +202,8 @@ static bool _list_extension(const struct sieve_extension *ext)
 	if ( *ext->name == '@' ) return FALSE;
 
 	if ( ext->validator_load == NULL && ext->generator_load == NULL &&
-		ext->binary_load == NULL && ext->runtime_load == NULL &&
-		ext->load == NULL && 
+		ext->binary_load == NULL && ext->interpreter_load == NULL &&
+		ext->runtime_load == NULL && ext->load == NULL &&
 		ext->operations.count == 0 && ext->operands.count == 0 ) {
 		return FALSE;
 	}
diff --git a/src/lib-sieve/sieve-extensions.h b/src/lib-sieve/sieve-extensions.h
index 0f5bff4152080070b437fe9b2234134cbbb7e69f..d60dc9067d4bec3cf07bff1e4ac01092a24201de 100644
--- a/src/lib-sieve/sieve-extensions.h
+++ b/src/lib-sieve/sieve-extensions.h
@@ -20,6 +20,7 @@ struct sieve_extension {
 
 	bool (*validator_load)(struct sieve_validator *validator);	
 	bool (*generator_load)(struct sieve_generator *generator);
+	bool (*interpreter_load)(struct sieve_interpreter *interpreter);
 	
 	bool (*runtime_load)(const struct sieve_runtime_env *renv);
 	
diff --git a/src/lib-sieve/sieve-interpreter.c b/src/lib-sieve/sieve-interpreter.c
index 067a5b56ce5b9a6e37baedc512624912923d3ed0..15e3b43d9996768ac3eddbed089fd6026d7cc836 100644
--- a/src/lib-sieve/sieve-interpreter.c
+++ b/src/lib-sieve/sieve-interpreter.c
@@ -48,6 +48,9 @@ struct sieve_interpreter {
 struct sieve_interpreter *sieve_interpreter_create
 (struct sieve_binary *sbin, struct sieve_error_handler *ehandler) 
 {
+	unsigned int i;
+	int idx;
+
 	pool_t pool;
 	struct sieve_interpreter *interp;
 	
@@ -66,6 +69,23 @@ struct sieve_interpreter *sieve_interpreter_create
 	interp->pc = 0;
 
 	p_array_init(&interp->ext_contexts, pool, 4);
+
+	/* Pre-load core language features implemented as 'extensions' */
+	for ( i = 0; i < sieve_preloaded_extensions_count; i++ ) {
+		const struct sieve_extension *ext = sieve_preloaded_extensions[i];
+		
+		if ( ext->interpreter_load != NULL )
+			(void)ext->interpreter_load(interp);		
+	}
+
+	/* Load other extensions listed in the binary */
+	for ( idx = 0; idx < sieve_binary_extensions_count(sbin); idx++ ) {
+		const struct sieve_extension *ext = 
+			sieve_binary_extension_get_by_index(sbin, idx, NULL);
+		
+		if ( ext->interpreter_load != NULL )
+			ext->interpreter_load(interp);
+	}
 	
 	return interp;
 }
diff --git a/src/lib-sieve/sieve-match-types.c b/src/lib-sieve/sieve-match-types.c
index 8a710e4c3314ada56b3dbf35b14e71888d3bef99..437dbb26a4c27cd9955ac88721b3d7b0b4a23e86 100644
--- a/src/lib-sieve/sieve-match-types.c
+++ b/src/lib-sieve/sieve-match-types.c
@@ -55,8 +55,7 @@ const struct sieve_extension match_type_extension = {
 	"@match-types",
 	mtch_extension_load,
 	mtch_validator_load,
-	NULL,
-	NULL,
+	NULL, NULL, NULL,
 	mtch_binary_load,
 	NULL,
 	SIEVE_EXT_DEFINE_NO_OPERATIONS,
diff --git a/src/testsuite/ext-testsuite.c b/src/testsuite/ext-testsuite.c
index 7bccc2a3380716cabf72516f17efc7db10e88b62..bc2ccaec44479167c49a69dea0d53ab992375531 100644
--- a/src/testsuite/ext-testsuite.c
+++ b/src/testsuite/ext-testsuite.c
@@ -62,7 +62,7 @@ const struct sieve_extension testsuite_extension = {
 	ext_testsuite_load,
 	ext_testsuite_validator_load,
 	ext_testsuite_generator_load,
-	NULL,
+	NULL, NULL,
 	ext_testsuite_binary_load, 
 	NULL, 
 	SIEVE_EXT_DEFINE_OPERATIONS(testsuite_operations),