diff --git a/Modules/CMakeASM_NASMInformation.cmake b/Modules/CMakeASM_NASMInformation.cmake
index 449d1d6a65566238bb605454dfb812de6c615486..9da7d306c27cece5dcdf1a895ef0b4f5540ff66d 100644
--- a/Modules/CMakeASM_NASMInformation.cmake
+++ b/Modules/CMakeASM_NASMInformation.cmake
@@ -16,27 +16,29 @@
 
 set(CMAKE_ASM_NASM_SOURCE_FILE_EXTENSIONS nasm asm)
 
-if(WIN32)
-  if(CMAKE_C_SIZEOF_DATA_PTR EQUAL 8)
-    SET(CMAKE_ASM_NASM_OBJECT_FORMAT win64)
+if(NOT CMAKE_ASM_NASM_OBJECT_FORMAT)
+  if(WIN32)
+    if(CMAKE_C_SIZEOF_DATA_PTR EQUAL 8)
+      SET(CMAKE_ASM_NASM_OBJECT_FORMAT win64)
+    else()
+      SET(CMAKE_ASM_NASM_OBJECT_FORMAT win32)
+    endif()
+  elseif(APPLE)
+    if(CMAKE_C_SIZEOF_DATA_PTR EQUAL 8)
+      SET(CMAKE_ASM_NASM_OBJECT_FORMAT macho64)
+    else()
+      SET(CMAKE_ASM_NASM_OBJECT_FORMAT macho)
+    endif()
   else()
-    SET(CMAKE_ASM_NASM_OBJECT_FORMAT win32)
-  endif()
-elseif(APPLE)
-  if(CMAKE_C_SIZEOF_DATA_PTR EQUAL 8)
-    SET(CMAKE_ASM_NASM_OBJECT_FORMAT macho64)
-  else()
-    SET(CMAKE_ASM_NASM_OBJECT_FORMAT macho)
-  endif()
-else()
-  if(CMAKE_C_SIZEOF_DATA_PTR EQUAL 8)
-    SET(CMAKE_ASM_NASM_OBJECT_FORMAT elf64)
-  else()
-    SET(CMAKE_ASM_NASM_OBJECT_FORMAT elf)
+    if(CMAKE_C_SIZEOF_DATA_PTR EQUAL 8)
+      SET(CMAKE_ASM_NASM_OBJECT_FORMAT elf64)
+    else()
+      SET(CMAKE_ASM_NASM_OBJECT_FORMAT elf)
+    endif()
   endif()
 endif()
 
-set(CMAKE_ASM_NASM_COMPILE_OBJECT "<CMAKE_ASM_NASM_COMPILER> <CMAKE_ASM_NASM_FLAGS> -f ${CMAKE_ASM_NASM_OBJECT_FORMAT} -o <OBJECT> <SOURCE>")
+set(CMAKE_ASM_NASM_COMPILE_OBJECT "<CMAKE_ASM_NASM_COMPILER> <FLAGS> -f ${CMAKE_ASM_NASM_OBJECT_FORMAT} -o <OBJECT> <SOURCE>")
 
 # Load the generic ASMInformation file:
 set(ASM_DIALECT "_NASM")