diff --git a/include/internal/catch_matchers_floating.cpp b/include/internal/catch_matchers_floating.cpp
index bcca0725d3..40cea7c76f 100644
--- a/include/internal/catch_matchers_floating.cpp
+++ b/include/internal/catch_matchers_floating.cpp
@@ -55,7 +55,7 @@ namespace {
             return lhs == rhs;
         }
 
-        auto ulpDiff = std::abs(lc - rc);
+        auto ulpDiff = std::abs(static_cast<FP>(lc - rc));
         return static_cast<uint64_t>(ulpDiff) <= maxUlpDiff;
     }