diff --git a/src/main/java/net/fabricmc/loom/util/Checksum.java b/src/main/java/net/fabricmc/loom/util/Checksum.java
index d90493fd..50fcbec0 100644
--- a/src/main/java/net/fabricmc/loom/util/Checksum.java
+++ b/src/main/java/net/fabricmc/loom/util/Checksum.java
@@ -96,6 +96,7 @@ public class Checksum {
 
 	public static String projectHash(Project project) {
 		String str = project.getProjectDir().getAbsolutePath() + ":" + project.getPath();
-		return toHex(str.getBytes(StandardCharsets.UTF_8)).substring(0, 16);
+		String hex = sha1Hex(str.getBytes(StandardCharsets.UTF_8));
+		return hex.substring(hex.length() - 16);
 	}
 }