diff --git a/src/ifcexpressparser/schema_class.py b/src/ifcexpressparser/schema_class.py
index 51b10e1aa8..ce76172954 100644
--- a/src/ifcexpressparser/schema_class.py
+++ b/src/ifcexpressparser/schema_class.py
@@ -91,7 +91,11 @@ class SchemaClass(codegen.Base):
         statements.append("{factory_placeholder}")
                       
         statements.append("""
-#ifdef _MSC_VER
+#if defined(__clang__)
+#elif defined(__GNUC__) || defined(__GNUG__)
+#pragma GCC push_options
+#pragma GCC optimize ("O0")
+#elif defined(_MSC_VER)
 #pragma optimize("", off)
 #endif
         """)
@@ -198,7 +202,10 @@ class SchemaClass(codegen.Base):
         statements.extend(('}',''))
         
         statements.append("""
-#ifdef _MSC_VER
+#if defined(__clang__)
+#elif defined(__GNUC__) || defined(__GNUG__)
+#pragma GCC pop_options
+#elif defined(_MSC_VER)
 #pragma optimize("", on)
 #endif
         """)
diff --git a/src/ifcparse/Ifc2x3-schema.cpp b/src/ifcparse/Ifc2x3-schema.cpp
index edb7d8eb39..40e56e01bc 100644
--- a/src/ifcparse/Ifc2x3-schema.cpp
+++ b/src/ifcparse/Ifc2x3-schema.cpp
@@ -1790,7 +1790,11 @@ class IFC2X3_instance_factory : public IfcParse::instance_factory {
 };
 
 
-#ifdef _MSC_VER
+#if defined(__clang__)
+#elif defined(__GNUC__) || defined(__GNUG__)
+#pragma GCC push_options
+#pragma GCC optimize ("O0")
+#elif defined(_MSC_VER)
 #pragma optimize("", off)
 #endif
         
@@ -11527,7 +11531,10 @@ IfcParse::schema_definition* IFC2X3_populate_schema() {
 }
 
 
-#ifdef _MSC_VER
+#if defined(__clang__)
+#elif defined(__GNUC__) || defined(__GNUG__)
+#pragma GCC pop_options
+#elif defined(_MSC_VER)
 #pragma optimize("", on)
 #endif
         
diff --git a/src/ifcparse/Ifc4-schema.cpp b/src/ifcparse/Ifc4-schema.cpp
index a64c2d5c85..e6004470e0 100644
--- a/src/ifcparse/Ifc4-schema.cpp
+++ b/src/ifcparse/Ifc4-schema.cpp
@@ -2104,7 +2104,11 @@ class IFC4_instance_factory : public IfcParse::instance_factory {
 };
 
 
-#ifdef _MSC_VER
+#if defined(__clang__)
+#elif defined(__GNUC__) || defined(__GNUG__)
+#pragma GCC push_options
+#pragma GCC optimize ("O0")
+#elif defined(_MSC_VER)
 #pragma optimize("", off)
 #endif
         
@@ -13701,7 +13705,10 @@ IfcParse::schema_definition* IFC4_populate_schema() {
 }
 
 
-#ifdef _MSC_VER
+#if defined(__clang__)
+#elif defined(__GNUC__) || defined(__GNUG__)
+#pragma GCC pop_options
+#elif defined(_MSC_VER)
 #pragma optimize("", on)
 #endif