diff --git a/src/Makefile.d/nix.mk b/src/Makefile.d/nix.mk
index 9adf3f0f14fdc2b052e48053cabedee48a1a7edd..c4fa3640f8e4cfaecfa339c5356d1a0f4ee6fb46 100644
--- a/src/Makefile.d/nix.mk
+++ b/src/Makefile.d/nix.mk
@@ -14,7 +14,11 @@ opts+=-I/usr/X11R6/include
 libs+=-L/usr/X11R6/lib
 endif
 
+ifndef DEDICATED
+ifndef DUMMY
 SDL?=1
+endif
+endif
 
 # In common usage.
 ifdef LINUX
diff --git a/src/Makefile.d/win32.mk b/src/Makefile.d/win32.mk
index 3e60e2416318f752a45261d14d9c349205fdb8ac..51523a212463172ebdffec37e3a798c8fad5a850 100644
--- a/src/Makefile.d/win32.mk
+++ b/src/Makefile.d/win32.mk
@@ -17,7 +17,11 @@ sources+=win32/Srb2win.rc
 opts+=-DSTDC_HEADERS
 libs+=-ladvapi32 -lkernel32 -lmsvcrt -luser32
 
+ifndef DEDICATED
+ifndef DUMMY
 SDL?=1
+endif
+endif
 
 ifndef NOHW
 opts+=-DUSE_WGL_SWAP