diff --git a/regression/ansi-c/sizeof1/main.c b/regression/ansi-c/sizeof1/main.c
index 936e3024cbc..e3612b9b29e 100644
--- a/regression/ansi-c/sizeof1/main.c
+++ b/regression/ansi-c/sizeof1/main.c
@@ -12,16 +12,20 @@ STATIC_ASSERT(sizeof(void *)==sizeof(size_t));
 
 #ifdef _WIN32
 
-#ifdef _WIN64
+#  ifdef _WIN64
 
 STATIC_ASSERT(sizeof(void *)==8);
 STATIC_ASSERT(sizeof(int)==4);
 STATIC_ASSERT(sizeof(long int)==4);
 STATIC_ASSERT(sizeof(long long int)==8);
 STATIC_ASSERT(sizeof(wchar_t)==2);
+#    ifdef __MINGW64__
+STATIC_ASSERT(sizeof(long double) == 16);
+#    else
 STATIC_ASSERT(sizeof(long double)==8);
+#    endif
 
-#else
+#  else
 
 STATIC_ASSERT(sizeof(void *)==4);
 STATIC_ASSERT(sizeof(int)==4);
@@ -30,7 +34,7 @@ STATIC_ASSERT(sizeof(long long int)==8);
 STATIC_ASSERT(sizeof(wchar_t)==2);
 STATIC_ASSERT(sizeof(long double)==8);
 
-#endif
+#  endif
 
 #else
 
diff --git a/src/util/config.cpp b/src/util/config.cpp
index c39d528f129..51b39f0894d 100644
--- a/src/util/config.cpp
+++ b/src/util/config.cpp
@@ -993,7 +993,7 @@ bool configt::set(const cmdlinet &cmdline)
 
     // long double is the same as double in Visual Studio,
     // but it's 16 bytes with GCC with the 64-bit target.
-    if(arch=="x64_64" && cmdline.isset("gcc"))
+    if(arch == "x86_64" && cmdline.isset("gcc"))
       ansi_c.long_double_width=16*8;
     else
       ansi_c.long_double_width=8*8;