diff --git a/Source/Tests/compression.cpp b/Source/Tests/compression.cpp
index f38ab3a1..16398ca9 100644
--- a/Source/Tests/compression.cpp
+++ b/Source/Tests/compression.cpp
@@ -18,7 +18,10 @@ public:
     srand(time(0));
 
     for (int i = 0; i < kb; i++) {
-      int r = rand();
+      int r;
+      do 
+        r = rand();
+      while (0x3dd0def3 == r); // Temporary workaround for https://sf.net/p/nsis/bugs/1156/#zlibCompressionTest loops endlessly
       for (size_t j = 0; j < 1024/sizeof(int); j++) {
         buf.add(&r, sizeof(int));
       }
@@ -89,11 +92,13 @@ public:
     CPPUNIT_ASSERT_EQUAL( C_OK, compressor.Init(9, 1 << 23) );
     testCompressDecompress(1024, compressor, decompressor);
 
+#ifndef NSIS_TESTS_FASTCOMPRESSIONONLY
     CPPUNIT_ASSERT_EQUAL( C_OK, compressor.Init(9, 1 << 23) );
     testCompressDecompress(8*1024, compressor, decompressor);
 
     CPPUNIT_ASSERT_EQUAL( C_OK, compressor.Init(9, 1 << 23) );
     testCompressDecompress(32*1024, compressor, decompressor);
+#endif
   }
 
 };