diff --git a/src/openexr.imageio/exroutput.cpp b/src/openexr.imageio/exroutput.cpp
index e89cb0a528..21bbd5e1db 100644
--- a/src/openexr.imageio/exroutput.cpp
+++ b/src/openexr.imageio/exroutput.cpp
@@ -22,9 +22,6 @@
 #include <OpenEXR/ImfTiledOutputFile.h>
 
 #include "exr_pvt.h"
-#define OPENEXR_CODED_VERSION                                    \
-    (OPENEXR_VERSION_MAJOR * 10000 + OPENEXR_VERSION_MINOR * 100 \
-     + OPENEXR_VERSION_PATCH)
 
 // The way that OpenEXR uses dynamic casting for attributes requires
 // temporarily suspending "hidden" symbol visibility mode.
@@ -734,16 +731,32 @@ OpenEXROutput::spec_to_header(ImageSpec& spec, int subimage,
             || !ispow2(spec.tile_width) || !ispow2(spec.tile_height))) {
         comp = "zip";
     }
-    if (Strutil::istarts_with(comp, "dwa")) {
-        spec.attribute("openexr:dwaCompressionLevel",
-                       qual > 0 ? float(qual) : 45.0f);
-    }
     spec.attribute("compression", comp);
+
+    // Zip and DWA compression have additional ways to set the levels
 #if OPENEXR_CODED_VERSION >= 30103
+    // OpenEXR 3.1.3 and later allow us to pick the uquality level. We've
+    // found that 4 is a great tradeoff between size and speed, so that is our
+    // default.
     if (Strutil::istarts_with(comp, "zip")) {
         header.zipCompressionLevel() = (qual >= 1 && qual <= 9) ? qual : 4;
     }
 #endif
+    if (Strutil::istarts_with(comp, "dwa") && qual > 0) {
+#if OPENEXR_CODED_VERSION >= 30103
+        // OpenEXR 3.1.3 and later have an API for setting the quality level
+        // in the Header object. Older ones do it by setting an attribute, as
+        // below.
+        header.dwaCompressionLevel() = float(qual);
+#endif
+        // We set this attribute even for older openexr, because even if
+        // we set in the header (above), it gets saved as metadata in the
+        // file so that when we re-read it, we know what the compression
+        // level was.
+        spec.attribute("openexr:dwaCompressionLevel", float(qual));
+    } else {
+        spec.erase_attribute("openexr:dwaCompressionLevel");
+    }
 
     // Default to increasingY line order
     if (!spec.find_attribute("openexr:lineOrder"))