diff --git a/sysconfig.h b/sysconfig.h
index e68fa76a..fe2d199e 100644
--- a/sysconfig.h
+++ b/sysconfig.h
@@ -78,6 +78,10 @@
 #define CAP_THREAD (!ISMOBILE && !ISWEB)
 #endif
 
+#ifndef CAP_ZLIB
+#define CAP_ZLIB (MAXMDIM >= 4)
+#endif
+
 #define CAP_FRAMELIMIT (!ISMOBWEB)
 
 #if ISMOBILE
@@ -168,6 +172,10 @@
 #define CAP_ODS 0
 #endif
 
+#ifndef MAXMDIM
+#define MAXMDIM 4
+#endif
+
 #ifndef CAP_TEXTURE
 #define CAP_TEXTURE (CAP_GL && (CAP_PNG || CAP_SDL_IMG) && !ISMINI)
 #endif
@@ -426,7 +434,9 @@ extern "C" {
 #include <complex>
 #include <new>
 
+#if CAP_ZLIB
 #include <zlib.h>
+#endif
 
 #if CAP_THREAD
 #if WINDOWS
@@ -494,10 +504,6 @@ union SDL_Event;
 #endif
 #endif
 
-#ifndef MAXMDIM
-#define MAXMDIM 4
-#endif
-
 #ifndef CAP_GEOMETRY
 #define CAP_GEOMETRY (!(ISMINI))
 #endif
diff --git a/util.cpp b/util.cpp
index 7983f16d..81491cbf 100644
--- a/util.cpp
+++ b/util.cpp
@@ -523,6 +523,7 @@ bignum::bignum(ld d) {
   while(n >= 0) { digits[n] = int(d); d -= digits[n]; d *= BASE; n--; }
   }
 
+#if CAP_ZLIB
 /* compression/decompression */
 
 EX string compress_string(string s) {
@@ -563,5 +564,6 @@ EX string decompress_string(string s) {
   println(hlog, isize(s), " -> ", isize(out));
   return out;
   }
+#endif
 
 }