diff --git a/libaudiofile/modules/SimpleModule.h b/libaudiofile/modules/SimpleModule.h
index 03c6c69..8e453a7 100644
--- a/libaudiofile/modules/SimpleModule.h
+++ b/libaudiofile/modules/SimpleModule.h
@@ -123,7 +123,7 @@ struct signConverter
 	typedef typename IntTypes<Format>::UnsignedType UnsignedType;
 
 	static const int kScaleBits = (Format + 1) * CHAR_BIT - 1;
-	static const int kMinSignedValue = -1 << kScaleBits;
+	static const int kMinSignedValue = -1U << kScaleBits;
 
 	struct signedToUnsigned : public std::unary_function<SignedType, UnsignedType>
 	{
diff --git a/test/FloatToInt.cpp b/test/FloatToInt.cpp
index 0d179a8..624be25 100644
--- a/test/FloatToInt.cpp
+++ b/test/FloatToInt.cpp
@@ -115,7 +115,7 @@ TEST_F(FloatToIntTest, Int16)
 		EXPECT_EQ(readData[i], expectedData[i]);
 }
 
-static const int32_t kMinInt24 = -1<<23;
+static const int32_t kMinInt24 = -1U<<23;
 static const int32_t kMaxInt24 = (1<<23) - 1;
 
 TEST_F(FloatToIntTest, Int24)
diff --git a/test/IntToFloat.cpp b/test/IntToFloat.cpp
index b716635..b619a2c 100644
--- a/test/IntToFloat.cpp
+++ b/test/IntToFloat.cpp
@@ -117,7 +117,7 @@ TEST_F(IntToFloatTest, Int16)
 		EXPECT_EQ(readData[i], expectedData[i]);
 }
 
-static const int32_t kMinInt24 = -1<<23;
+static const int32_t kMinInt24 = -1U<<23;
 static const int32_t kMaxInt24 = (1<<23) - 1;
 
 TEST_F(IntToFloatTest, Int24)
diff --git a/test/Sign.cpp b/test/Sign.cpp
index 7275399..b3609ca 100644
--- a/test/Sign.cpp
+++ b/test/Sign.cpp
@@ -116,7 +116,7 @@ TEST_F(SignConversionTest, Int16)
 		EXPECT_EQ(readData[i], expectedData[i]);
 }
 
-static const int32_t kMinInt24 = -1<<23;
+static const int32_t kMinInt24 = -1U<<23;
 static const int32_t kMaxInt24 = (1<<23) - 1;
 static const uint32_t kMaxUInt24 = (1<<24) - 1;