diff --git a/doc/langref.md b/doc/langref.md
index a83aecf82..cc4f5001d 100644
--- a/doc/langref.md
+++ b/doc/langref.md
@@ -204,7 +204,7 @@ c_long          long                for ABI compatibility with C
 c_ulong         unsigned long       for ABI compatibility with C
 c_longlong      long long           for ABI compatibility with C
 c_ulonglong     unsigned long long  for ABI compatibility with C
-c_long_double   long double         for ABI compatibility with C
+c_longdouble    long double         for ABI compatibility with C
 c_void          void                for ABI compatibility with C
 
 f32             float               32-bit floating point
diff --git a/src/all_types.hpp b/src/all_types.hpp
index 152b29faf..9277fa2c6 100644
--- a/src/all_types.hpp
+++ b/src/all_types.hpp
@@ -1360,7 +1360,7 @@ struct CodeGen {
         TypeTableEntry *entry_bool;
         TypeTableEntry *entry_int[2][4]; // [signed,unsigned][8,16,32,64]
         TypeTableEntry *entry_c_int[CIntTypeCount];
-        TypeTableEntry *entry_c_long_double;
+        TypeTableEntry *entry_c_longdouble;
         TypeTableEntry *entry_c_void;
         TypeTableEntry *entry_u8;
         TypeTableEntry *entry_u16;
diff --git a/src/codegen.cpp b/src/codegen.cpp
index 49dec3589..3da7fb186 100644
--- a/src/codegen.cpp
+++ b/src/codegen.cpp
@@ -4250,14 +4250,14 @@ static void define_builtin_types(CodeGen *g) {
     {
         TypeTableEntry *entry = new_type_table_entry(TypeTableEntryIdFloat);
         entry->type_ref = LLVMX86FP80Type();
-        buf_init_from_str(&entry->name, "c_long_double");
+        buf_init_from_str(&entry->name, "c_longdouble");
         entry->data.floating.bit_count = 80;
 
         uint64_t debug_size_in_bits = 8*LLVMStoreSizeOfType(g->target_data_ref, entry->type_ref);
         entry->di_type = ZigLLVMCreateDebugBasicType(g->dbuilder, buf_ptr(&entry->name),
                 debug_size_in_bits,
                 ZigLLVMEncoding_DW_ATE_float());
-        g->builtin_types.entry_c_long_double = entry;
+        g->builtin_types.entry_c_longdouble = entry;
         g->primitive_type_table.put(&entry->name, entry);
     }
     {
@@ -4902,7 +4902,7 @@ static void get_c_type(CodeGen *g, TypeTableEntry *type_entry, Buf *out_buf) {
             return;
         }
     }
-    if (type_entry == g->builtin_types.entry_c_long_double) {
+    if (type_entry == g->builtin_types.entry_c_longdouble) {
         buf_init_from_str(out_buf, "long double");
         return;
     }
diff --git a/src/parseh.cpp b/src/parseh.cpp
index 8780e0424..f7248a808 100644
--- a/src/parseh.cpp
+++ b/src/parseh.cpp
@@ -275,7 +275,7 @@ static TypeTableEntry *resolve_type_with_table(Context *c, const Type *ty, const
                     case BuiltinType::Double:
                         return c->codegen->builtin_types.entry_f64;
                     case BuiltinType::LongDouble:
-                        return c->codegen->builtin_types.entry_c_long_double;
+                        return c->codegen->builtin_types.entry_c_longdouble;
                     case BuiltinType::WChar_U:
                     case BuiltinType::Char16:
                     case BuiltinType::Char32: