diff --git a/configure b/configure
index 9f06d6193eb..3e8b30eb567 100755
--- a/configure
+++ b/configure
@@ -766,6 +766,7 @@ SUBDIRS
 READELF
 OTOOL
 LDD
+DLLEXT
 WINEPRELOADER_LDFLAGS
 WINELOADER_LDFLAGS
 TOP_INSTALL_DEV
@@ -9146,6 +9147,8 @@ WINELOADER_LDFLAGS=""
 
 WINEPRELOADER_LDFLAGS=""
 
+DLLEXT=".so"
+
 LIBEXT="so"
 # Extract the first word of "ldd", so it can be a program name with args.
 set dummy ldd; ac_word=$2
@@ -9437,6 +9440,7 @@ $ac_links:
 case $host_os in
   cygwin*|mingw32*)
     LIBEXT="dll"
+    DLLEXT=""
     EXTRACFLAGS="-D__WINE_PE_BUILD"
         case $host_cpu in
       *i[3456]86*) { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether the compiler supports -Wl,--disable-stdcall-fixup" >&5
@@ -23204,6 +23208,7 @@ TOP_INSTALL_LIB = $TOP_INSTALL_LIB
 TOP_INSTALL_DEV = $TOP_INSTALL_DEV
 WINELOADER_LDFLAGS = $WINELOADER_LDFLAGS
 WINEPRELOADER_LDFLAGS = $WINEPRELOADER_LDFLAGS
+DLLEXT = $DLLEXT
 LDD = $LDD
 OTOOL = $OTOOL
 READELF = $READELF
diff --git a/configure.ac b/configure.ac
index 7a4af2d454e..1c17475ce80 100644
--- a/configure.ac
+++ b/configure.ac
@@ -643,6 +643,7 @@ AC_SUBST(TOP_INSTALL_LIB,"")
 AC_SUBST(TOP_INSTALL_DEV,"")
 AC_SUBST(WINELOADER_LDFLAGS,"")
 AC_SUBST(WINEPRELOADER_LDFLAGS,"")
+AC_SUBST(DLLEXT,".so")
 LIBEXT="so"
 WINE_PATH_SONAME_TOOLS
 WINE_CONFIG_HELPERS
@@ -650,6 +651,7 @@ WINE_CONFIG_HELPERS
 case $host_os in
   cygwin*|mingw32*)
     LIBEXT="dll"
+    DLLEXT=""
     EXTRACFLAGS="-D__WINE_PE_BUILD"
     dnl Disable stdcall fixups to catch prototype mismatches
     case $host_cpu in
diff --git a/tools/makedep.c b/tools/makedep.c
index 3322e825617..7f6772e5203 100644
--- a/tools/makedep.c
+++ b/tools/makedep.c
@@ -4407,7 +4407,7 @@ int main( int argc, char *argv[] )
     tools_dir          = get_expanded_make_variable( top_makefile, "toolsdir" );
     tools_ext          = get_expanded_make_variable( top_makefile, "toolsext" );
     exe_ext            = get_expanded_make_variable( top_makefile, "EXEEXT" );
-    dll_ext            = (exe_ext && !strcmp( exe_ext, ".exe" )) ? "" : ".so";
+    dll_ext            = get_expanded_make_variable( top_makefile, "DLLEXT" );
     fontforge          = get_expanded_make_variable( top_makefile, "FONTFORGE" );
     convert            = get_expanded_make_variable( top_makefile, "CONVERT" );
     flex               = get_expanded_make_variable( top_makefile, "FLEX" );
@@ -4424,6 +4424,7 @@ int main( int argc, char *argv[] )
     if (root_src_dir && !strcmp( root_src_dir, "." )) root_src_dir = NULL;
     if (tools_dir && !strcmp( tools_dir, "." )) tools_dir = NULL;
     if (!exe_ext) exe_ext = "";
+    if (!dll_ext) dll_ext = "";
     if (!tools_ext) tools_ext = "";
 
     strarray_add( &archs, get_expanded_make_variable( top_makefile, "HOST_ARCH" ));