diff --git a/jerry-core/ecma/builtin-objects/ecma-builtin-regexp-prototype.c b/jerry-core/ecma/builtin-objects/ecma-builtin-regexp-prototype.c
index aacc0fd03e..32637b1ebc 100644
--- a/jerry-core/ecma/builtin-objects/ecma-builtin-regexp-prototype.c
+++ b/jerry-core/ecma/builtin-objects/ecma-builtin-regexp-prototype.c
@@ -132,7 +132,7 @@ ecma_builtin_regexp_prototype_compile (ecma_value_t this_arg, /**< this argument
         /* FIXME: "We currently have to re-compile the bytecode, because
          * we can't copy it without knowing its length."
          */
-        re_compiled_code_t *new_bc_p = NULL;
+        const re_compiled_code_t *new_bc_p = NULL;
         ecma_value_t bc_comp = re_compile_bytecode (&new_bc_p, pattern_string_p, flags);
         /* Should always succeed, since we're compiling from a source that has been compiled previously. */
         JERRY_ASSERT (ecma_is_value_empty (bc_comp));
@@ -201,7 +201,7 @@ ecma_builtin_regexp_prototype_compile (ecma_value_t this_arg, /**< this argument
         ecma_property_t *bc_prop_p = ecma_get_internal_property (this_obj_p,
                                                                  ECMA_INTERNAL_PROPERTY_REGEXP_BYTECODE);
         /* Try to compile bytecode from new source. */
-        re_compiled_code_t *new_bc_p = NULL;
+        const re_compiled_code_t *new_bc_p = NULL;
         ECMA_TRY_CATCH (bc_dummy,
                         re_compile_bytecode (&new_bc_p, pattern_string_p, flags),
                         ret_value);
diff --git a/jerry-core/ecma/operations/ecma-regexp-object.c b/jerry-core/ecma/operations/ecma-regexp-object.c
index 97d4eff0da..4048a56442 100644
--- a/jerry-core/ecma/operations/ecma-regexp-object.c
+++ b/jerry-core/ecma/operations/ecma-regexp-object.c
@@ -306,7 +306,7 @@ ecma_op_create_regexp_object (ecma_string_t *pattern_p, /**< input pattern */
   bytecode_prop_p = ecma_create_internal_property (obj_p, ECMA_INTERNAL_PROPERTY_REGEXP_BYTECODE);
 
   /* Compile bytecode. */
-  re_compiled_code_t *bc_p = NULL;
+  const re_compiled_code_t *bc_p = NULL;
   ECMA_TRY_CATCH (empty, re_compile_bytecode (&bc_p, pattern_p, flags), ret_value);
 
   ECMA_SET_POINTER (bytecode_prop_p->v.internal_property.value, bc_p);
diff --git a/jerry-core/jerry.c b/jerry-core/jerry.c
index 443fcf8d4a..292c3dee4e 100644
--- a/jerry-core/jerry.c
+++ b/jerry-core/jerry.c
@@ -2171,7 +2171,7 @@ snapshot_load_compiled_code (const uint8_t *snapshot_data_p, /**< snapshot data
   if (!(bytecode_p->status_flags & CBC_CODE_FLAGS_FUNCTION))
   {
 #ifndef CONFIG_ECMA_COMPACT_PROFILE_DISABLE_REGEXP_BUILTIN
-    re_compiled_code_t *re_bytecode_p = NULL;
+    const re_compiled_code_t *re_bytecode_p = NULL;
 
     const uint8_t *regex_start_p = ((const uint8_t *) bytecode_p) + sizeof (uint16_t);
 
diff --git a/jerry-core/lit/lit-literal.c b/jerry-core/lit/lit-literal.c
index 323617a7cd..f9fc84af3c 100644
--- a/jerry-core/lit/lit-literal.c
+++ b/jerry-core/lit/lit-literal.c
@@ -129,7 +129,7 @@ lit_find_literal_by_utf8_string (const lit_utf8_byte_t *str_p, /**< a string to
           continue;
         }
 
-        if (!strncmp (rec_p + 1, (const char *) str_p, str_size))
+        if (!strncmp ((const char *) (rec_p + 1), (const char *) str_p, str_size))
         {
           return lit;
         }
diff --git a/jerry-core/mem/mem-heap.c b/jerry-core/mem/mem-heap.c
index a522b2926f..db651c97cc 100644
--- a/jerry-core/mem/mem-heap.c
+++ b/jerry-core/mem/mem-heap.c
@@ -260,7 +260,7 @@ void *mem_heap_alloc_block_internal (const size_t size)
     }
     else
     {
-      JERRY_ASSERT (MEM_HEAP_GET_ADDR_FROM_OFFSET (mem_heap.first.next_offset)->size > MEM_ALIGNMENT);
+      JERRY_ASSERT (data_space_p->size > MEM_ALIGNMENT);
       mem_heap_free_t *const remaining_p = MEM_HEAP_GET_ADDR_FROM_OFFSET (mem_heap.first.next_offset) + 1;
 
       VALGRIND_DEFINED_SPACE (remaining_p, sizeof (mem_heap_free_t));
diff --git a/jerry-core/mem/mem-poolman.c b/jerry-core/mem/mem-poolman.c
index fde5c5d361..0a66cda441 100644
--- a/jerry-core/mem/mem-poolman.c
+++ b/jerry-core/mem/mem-poolman.c
@@ -37,9 +37,9 @@
 /**
  * Node for free chunk list
  */
-typedef struct
+typedef struct mem_pools_chunk
 {
-  struct mem_pools_chunk_t *next_p; /* pointer to next pool chunk */
+  struct mem_pools_chunk *next_p; /* pointer to next pool chunk */
 #ifndef MEM_HEAP_PTR_64
   uint32_t dummy; /* dummy member for alignment */
 #endif
diff --git a/jerry-core/parser/js/js-lexer.c b/jerry-core/parser/js/js-lexer.c
index 70e25b08e0..c155bef426 100644
--- a/jerry-core/parser/js/js-lexer.c
+++ b/jerry-core/parser/js/js-lexer.c
@@ -1808,7 +1808,7 @@ lexer_construct_regexp_object (parser_context_t *context_p, /**< context */
   context_p->literal_count++;
 
   /* Compile the RegExp literal and store the RegExp bytecode pointer */
-  re_compiled_code_t *re_bytecode_p = NULL;
+  const re_compiled_code_t *re_bytecode_p = NULL;
   ecma_value_t completion_value;
 
   ecma_string_t *pattern_str_p = ecma_new_ecma_string_from_utf8 (regex_start_p, length);
diff --git a/jerry-core/parser/regexp/re-compiler.c b/jerry-core/parser/regexp/re-compiler.c
index abc24ea7be..cbd2fd9834 100644
--- a/jerry-core/parser/regexp/re-compiler.c
+++ b/jerry-core/parser/regexp/re-compiler.c
@@ -41,12 +41,12 @@
  */
 static void
 re_append_char_class (void *re_ctx_p, /**< RegExp compiler context */
-                      ecma_char_t start, /**< character class range from */
-                      ecma_char_t end) /**< character class range to */
+                      uint32_t start, /**< character class range from */
+                      uint32_t end) /**< character class range to */
 {
   re_compiler_ctx_t *ctx_p = (re_compiler_ctx_t *) re_ctx_p;
-  re_append_char (ctx_p->bytecode_ctx_p, start);
-  re_append_char (ctx_p->bytecode_ctx_p, end);
+  re_append_char (ctx_p->bytecode_ctx_p, (ecma_char_t) start);
+  re_append_char (ctx_p->bytecode_ctx_p, (ecma_char_t) end);
   ctx_p->parser_ctx_p->num_of_classes++;
 } /* re_append_char_class */
 
@@ -452,7 +452,7 @@ static const re_compiled_code_t *re_cache[RE_CACHE_SIZE];
  * @return compiled bytecode - if found
  *         NULL              - otherwise
  */
-re_compiled_code_t *
+const re_compiled_code_t *
 re_find_bytecode_in_cache (ecma_string_t *pattern_str_p, /**< pattern string */
                            uint16_t flags, /**< flags */
                            uint32_t *idx) /**< [out] index */
@@ -461,7 +461,7 @@ re_find_bytecode_in_cache (ecma_string_t *pattern_str_p, /**< pattern string */
 
   for (*idx = 0u; *idx < RE_CACHE_SIZE; (*idx)++)
   {
-    re_compiled_code_t *cached_bytecode_p = re_cache[*idx];
+    const re_compiled_code_t *cached_bytecode_p = re_cache[*idx];
 
     if (cached_bytecode_p != NULL)
     {
@@ -495,13 +495,13 @@ re_cache_gc_run ()
 {
   for (uint32_t i = 0u; i < RE_CACHE_SIZE; i++)
   {
-    re_compiled_code_t *cached_bytecode_p = re_cache[i];
+    const re_compiled_code_t *cached_bytecode_p = re_cache[i];
 
     if (cached_bytecode_p != NULL
         && (cached_bytecode_p->flags >> ECMA_BYTECODE_REF_SHIFT) == 1)
     { /* Only the cache has reference for the bytecode */
 
-      ecma_bytecode_deref (cached_bytecode_p);
+      ecma_bytecode_deref ((ecma_compiled_code_t *) cached_bytecode_p);
       re_cache[i] = NULL;
     }
   }
@@ -516,7 +516,7 @@ re_cache_gc_run ()
  *         Returned value must be freed with ecma_free_value
  */
 ecma_value_t
-re_compile_bytecode (re_compiled_code_t **out_bytecode_p, /**< [out] pointer to bytecode */
+re_compile_bytecode (const re_compiled_code_t **out_bytecode_p, /**< [out] pointer to bytecode */
                      ecma_string_t *pattern_str_p, /**< pattern */
                      uint16_t flags) /**< flags */
 {
@@ -604,7 +604,7 @@ re_compile_bytecode (re_compiled_code_t **out_bytecode_p, /**< [out] pointer to
 
       if (cache_idx < RE_CACHE_SIZE)
       {
-        ecma_bytecode_ref (*out_bytecode_p);
+        ecma_bytecode_ref ((ecma_compiled_code_t *) *out_bytecode_p);
         re_cache[cache_idx] = *out_bytecode_p;
       }
       else
diff --git a/jerry-core/parser/regexp/re-compiler.h b/jerry-core/parser/regexp/re-compiler.h
index 37dbca0ec4..aa3572bf2f 100644
--- a/jerry-core/parser/regexp/re-compiler.h
+++ b/jerry-core/parser/regexp/re-compiler.h
@@ -48,9 +48,9 @@ typedef struct
 } re_compiler_ctx_t;
 
 ecma_value_t
-re_compile_bytecode (re_compiled_code_t **, ecma_string_t *, uint16_t);
+re_compile_bytecode (const re_compiled_code_t **, ecma_string_t *, uint16_t);
 
-re_compiled_code_t *
+const re_compiled_code_t *
 re_find_bytecode_in_cache (ecma_string_t *pattern_str_p, uint16_t flags, uint32_t *idx);
 
 void re_cache_gc_run ();