diff --git a/scripts/mbedtls_dev/crypto_knowledge.py b/scripts/mbedtls_dev/crypto_knowledge.py
index 819d92a..eab6f56 100644
--- a/scripts/mbedtls_dev/crypto_knowledge.py
+++ b/scripts/mbedtls_dev/crypto_knowledge.py
@@ -138,6 +138,9 @@
         """Whether the key type is for public keys."""
         return self.name.endswith('_PUBLIC_KEY')
 
+    DH_KEY_SIZES = {
+        'PSA_DH_FAMILY_RFC7919': (2048, 3072, 4096, 6144, 8192),
+    } # type: Dict[str, Tuple[int, ...]]
     ECC_KEY_SIZES = {
         'PSA_ECC_FAMILY_SECP_K1': (192, 224, 256),
         'PSA_ECC_FAMILY_SECP_R1': (225, 256, 384, 521),
@@ -175,6 +178,9 @@
         if self.private_type == 'PSA_KEY_TYPE_ECC_KEY_PAIR':
             assert self.params is not None
             return self.ECC_KEY_SIZES[self.params[0]]
+        if self.private_type == 'PSA_KEY_TYPE_DH_KEY_PAIR':
+            assert self.params is not None
+            return self.DH_KEY_SIZES[self.params[0]]
         return self.KEY_TYPE_SIZES[self.private_type]
 
     # "48657265006973206b6579a064617461"