diff --git a/src/lisp/lisp.c b/src/lisp/lisp.c
index 94611e261dbd4e515adb0437b37e1b5df0375d6a..c07a1d6ead55a44408773ad6b684d3ffd37a33de 100644
--- a/src/lisp/lisp.c
+++ b/src/lisp/lisp.c
@@ -657,8 +657,9 @@ main(int argc, const char *argv[], const char *envp[])
 		}
 		if (dynamic_space_size == 0) {
 		    dynamic_space_size = DYNAMIC_SPACE_SIZE;
-		}
-		dynamic_space_size *= 1024 * 1024;
+		} else {
+                    dynamic_space_size *= 1024 * 1024;
+                }
 	    }
 #endif
 	    if (dynamic_space_size > DYNAMIC_SPACE_SIZE) {