diff --git a/zipkin/src/main/java/zipkin2/Span.java b/zipkin/src/main/java/zipkin2/Span.java
index c69cc2c0e73..725771d3663 100644
--- a/zipkin/src/main/java/zipkin2/Span.java
+++ b/zipkin/src/main/java/zipkin2/Span.java
@@ -635,7 +635,6 @@ public static String normalizeTraceId(String traceId) {
     if (length > 32) throw new IllegalArgumentException("traceId.length > 32");
     int zeros = validateHexAndReturnZeroPrefix(traceId);
     if (zeros == length) throw new IllegalArgumentException("traceId is all zeros");
-    if (length == 15) throw new RuntimeException("WTF");
     if (length == 32 || length == 16) {
       if (length == 32 && zeros >= 16) return traceId.substring(16);
       return traceId;