diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index 5954004..06e4b95 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -374,10 +374,11 @@
 }
 
 # Calculate the input & output maximum content lengths set in the config
-MAX_CONTENT_LEN=$( ../scripts/config.py get MBEDTLS_SSL_MAX_CONTENT_LEN || echo "16384")
-MAX_IN_LEN=$( ../scripts/config.py get MBEDTLS_SSL_IN_CONTENT_LEN || echo "$MAX_CONTENT_LEN")
-MAX_OUT_LEN=$( ../scripts/config.py get MBEDTLS_SSL_OUT_CONTENT_LEN || echo "$MAX_CONTENT_LEN")
+MAX_CONTENT_LEN=$(get_config_value_or_default "MBEDTLS_SSL_MAX_CONTENT_LEN")
+MAX_IN_LEN=$(get_config_value_or_default "MBEDTLS_SSL_IN_CONTENT_LEN")
+MAX_OUT_LEN=$(get_config_value_or_default "MBEDTLS_SSL_OUT_CONTENT_LEN")
 
+# Calculate the maximum content length that fits both
 if [ "$MAX_IN_LEN" -lt "$MAX_CONTENT_LEN" ]; then
     MAX_CONTENT_LEN="$MAX_IN_LEN"
 fi
@@ -3151,13 +3152,8 @@
 
 # Tests for Max Fragment Length extension
 
-if [ "$MAX_CONTENT_LEN" -lt "4096" ]; then
-    printf '%s defines MBEDTLS_SSL_MAX_CONTENT_LEN to be less than 4096. Fragment length tests will fail.\n' "${CONFIG_H}"
-    exit 1
-fi
-
 if [ $MAX_CONTENT_LEN -ne 16384 ]; then
-    echo "Using non-default maximum content length $MAX_CONTENT_LEN"
+    echo "Using non-default maximum content length $MAX_CONTENT_LEN instead of 16384    "
 fi
 
 requires_config_enabled MBEDTLS_SSL_MAX_FRAGMENT_LENGTH
@@ -3224,7 +3220,7 @@
             -s "1 bytes read"
 
 requires_config_disabled MBEDTLS_SSL_MAX_FRAGMENT_LENGTH
-run_test    "Max fragment length DTLS: disabled, larger message" \
+run_test    "Max fragment length, DTLS: disabled, larger message" \
             "$P_SRV debug_level=3 dtls=1" \
             "$P_CLI debug_level=3 dtls=1 request_size=$(( $MAX_CONTENT_LEN + 1))" \
             1 \
@@ -3234,6 +3230,9 @@
             -S "Maximum output fragment length is 16384" \
             -c "fragment larger than.*maximum "
 
+# Make sure it was compiled with lengths over 4096
+requires_config_value_at_least "MBEDTLS_SSL_IN_CONTENT_LEN" 4096
+requires_config_value_at_least "MBEDTLS_SSL_OUT_CONTENT_LEN" 4096
 requires_config_enabled MBEDTLS_SSL_MAX_FRAGMENT_LENGTH
 run_test    "Max fragment length: used by client" \
             "$P_SRV debug_level=3" \
@@ -3248,6 +3247,8 @@
             -s "server hello, max_fragment_length extension" \
             -c "found max_fragment_length extension"
 
+requires_config_value_at_least "MBEDTLS_SSL_IN_CONTENT_LEN" 1024
+requires_config_value_at_least "MBEDTLS_SSL_OUT_CONTENT_LEN" 1024
 requires_config_enabled MBEDTLS_SSL_MAX_FRAGMENT_LENGTH
 run_test    "Max fragment length: client 512, server 1024" \
             "$P_SRV debug_level=3 max_frag_len=1024" \
@@ -3262,6 +3263,8 @@
             -s "server hello, max_fragment_length extension" \
             -c "found max_fragment_length extension"
 
+requires_config_value_at_least "MBEDTLS_SSL_IN_CONTENT_LEN" 2048
+requires_config_value_at_least "MBEDTLS_SSL_OUT_CONTENT_LEN" 2048
 requires_config_enabled MBEDTLS_SSL_MAX_FRAGMENT_LENGTH
 run_test    "Max fragment length: client 512, server 2048" \
             "$P_SRV debug_level=3 max_frag_len=2048" \
@@ -3276,6 +3279,8 @@
             -s "server hello, max_fragment_length extension" \
             -c "found max_fragment_length extension"
 
+requires_config_value_at_least "MBEDTLS_SSL_IN_CONTENT_LEN" 4096
+requires_config_value_at_least "MBEDTLS_SSL_OUT_CONTENT_LEN" 4096
 requires_config_enabled MBEDTLS_SSL_MAX_FRAGMENT_LENGTH
 run_test    "Max fragment length: client 512, server 4096" \
             "$P_SRV debug_level=3 max_frag_len=4096" \
@@ -3290,6 +3295,8 @@
             -s "server hello, max_fragment_length extension" \
             -c "found max_fragment_length extension"
 
+requires_config_value_at_least "MBEDTLS_SSL_IN_CONTENT_LEN" 1024
+requires_config_value_at_least "MBEDTLS_SSL_OUT_CONTENT_LEN" 1024
 requires_config_enabled MBEDTLS_SSL_MAX_FRAGMENT_LENGTH
 run_test    "Max fragment length: client 1024, server 512" \
             "$P_SRV debug_level=3 max_frag_len=512" \
@@ -3304,6 +3311,8 @@
             -s "server hello, max_fragment_length extension" \
             -c "found max_fragment_length extension"
 
+requires_config_value_at_least "MBEDTLS_SSL_IN_CONTENT_LEN" 2048
+requires_config_value_at_least "MBEDTLS_SSL_OUT_CONTENT_LEN" 2048
 requires_config_enabled MBEDTLS_SSL_MAX_FRAGMENT_LENGTH
 run_test    "Max fragment length: client 1024, server 2048" \
             "$P_SRV debug_level=3 max_frag_len=2048" \
@@ -3318,6 +3327,8 @@
             -s "server hello, max_fragment_length extension" \
             -c "found max_fragment_length extension"
 
+requires_config_value_at_least "MBEDTLS_SSL_IN_CONTENT_LEN" 4096
+requires_config_value_at_least "MBEDTLS_SSL_OUT_CONTENT_LEN" 4096
 requires_config_enabled MBEDTLS_SSL_MAX_FRAGMENT_LENGTH
 run_test    "Max fragment length: client 1024, server 4096" \
             "$P_SRV debug_level=3 max_frag_len=4096" \
@@ -3332,6 +3343,8 @@
             -s "server hello, max_fragment_length extension" \
             -c "found max_fragment_length extension"
 
+requires_config_value_at_least "MBEDTLS_SSL_IN_CONTENT_LEN" 2048
+requires_config_value_at_least "MBEDTLS_SSL_OUT_CONTENT_LEN" 2048
 requires_config_enabled MBEDTLS_SSL_MAX_FRAGMENT_LENGTH
 run_test    "Max fragment length: client 2048, server 512" \
             "$P_SRV debug_level=3 max_frag_len=512" \
@@ -3346,6 +3359,8 @@
             -s "server hello, max_fragment_length extension" \
             -c "found max_fragment_length extension"
 
+requires_config_value_at_least "MBEDTLS_SSL_IN_CONTENT_LEN" 2048
+requires_config_value_at_least "MBEDTLS_SSL_OUT_CONTENT_LEN" 2048
 requires_config_enabled MBEDTLS_SSL_MAX_FRAGMENT_LENGTH
 run_test    "Max fragment length: client 2048, server 1024" \
             "$P_SRV debug_level=3 max_frag_len=1024" \
@@ -3360,6 +3375,8 @@
             -s "server hello, max_fragment_length extension" \
             -c "found max_fragment_length extension"
 
+requires_config_value_at_least "MBEDTLS_SSL_IN_CONTENT_LEN" 4096
+requires_config_value_at_least "MBEDTLS_SSL_OUT_CONTENT_LEN" 4096
 requires_config_enabled MBEDTLS_SSL_MAX_FRAGMENT_LENGTH
 run_test    "Max fragment length: client 2048, server 4096" \
             "$P_SRV debug_level=3 max_frag_len=4096" \
@@ -3374,6 +3391,8 @@
             -s "server hello, max_fragment_length extension" \
             -c "found max_fragment_length extension"
 
+requires_config_value_at_least "MBEDTLS_SSL_IN_CONTENT_LEN" 4096
+requires_config_value_at_least "MBEDTLS_SSL_OUT_CONTENT_LEN" 4096
 requires_config_enabled MBEDTLS_SSL_MAX_FRAGMENT_LENGTH
 run_test    "Max fragment length: client 4096, server 512" \
             "$P_SRV debug_level=3 max_frag_len=512" \
@@ -3388,6 +3407,8 @@
             -s "server hello, max_fragment_length extension" \
             -c "found max_fragment_length extension"
 
+requires_config_value_at_least "MBEDTLS_SSL_IN_CONTENT_LEN" 4096
+requires_config_value_at_least "MBEDTLS_SSL_OUT_CONTENT_LEN" 4096
 requires_config_enabled MBEDTLS_SSL_MAX_FRAGMENT_LENGTH
 run_test    "Max fragment length: client 4096, server 1024" \
             "$P_SRV debug_level=3 max_frag_len=1024" \
@@ -3402,6 +3423,8 @@
             -s "server hello, max_fragment_length extension" \
             -c "found max_fragment_length extension"
 
+requires_config_value_at_least "MBEDTLS_SSL_IN_CONTENT_LEN" 4096
+requires_config_value_at_least "MBEDTLS_SSL_OUT_CONTENT_LEN" 4096
 requires_config_enabled MBEDTLS_SSL_MAX_FRAGMENT_LENGTH
 run_test    "Max fragment length: client 4096, server 2048" \
             "$P_SRV debug_level=3 max_frag_len=2048" \
@@ -3416,6 +3439,8 @@
             -s "server hello, max_fragment_length extension" \
             -c "found max_fragment_length extension"
 
+requires_config_value_at_least "MBEDTLS_SSL_IN_CONTENT_LEN" 4096
+requires_config_value_at_least "MBEDTLS_SSL_OUT_CONTENT_LEN" 4096
 requires_config_enabled MBEDTLS_SSL_MAX_FRAGMENT_LENGTH
 run_test    "Max fragment length: used by server" \
             "$P_SRV debug_level=3 max_frag_len=4096" \
@@ -3430,6 +3455,8 @@
             -S "server hello, max_fragment_length extension" \
             -C "found max_fragment_length extension"
 
+requires_config_value_at_least "MBEDTLS_SSL_IN_CONTENT_LEN" 4096
+requires_config_value_at_least "MBEDTLS_SSL_OUT_CONTENT_LEN" 4096
 requires_config_enabled MBEDTLS_SSL_MAX_FRAGMENT_LENGTH
 requires_gnutls
 run_test    "Max fragment length: gnutls server" \
@@ -3441,6 +3468,8 @@
             -c "client hello, adding max_fragment_length extension" \
             -c "found max_fragment_length extension"
 
+requires_config_value_at_least "MBEDTLS_SSL_IN_CONTENT_LEN" 2048
+requires_config_value_at_least "MBEDTLS_SSL_OUT_CONTENT_LEN" 2048
 requires_config_enabled MBEDTLS_SSL_MAX_FRAGMENT_LENGTH
 run_test    "Max fragment length: client, message just fits" \
             "$P_SRV debug_level=3" \
@@ -3457,6 +3486,8 @@
             -c "2048 bytes written in 1 fragments" \
             -s "2048 bytes read"
 
+requires_config_value_at_least "MBEDTLS_SSL_IN_CONTENT_LEN" 2048
+requires_config_value_at_least "MBEDTLS_SSL_OUT_CONTENT_LEN" 2048
 requires_config_enabled MBEDTLS_SSL_MAX_FRAGMENT_LENGTH
 run_test    "Max fragment length: client, larger message" \
             "$P_SRV debug_level=3" \
@@ -3474,6 +3505,8 @@
             -s "2048 bytes read" \
             -s "297 bytes read"
 
+requires_config_value_at_least "MBEDTLS_SSL_IN_CONTENT_LEN" 2048
+requires_config_value_at_least "MBEDTLS_SSL_OUT_CONTENT_LEN" 2048
 requires_config_enabled MBEDTLS_SSL_MAX_FRAGMENT_LENGTH
 run_test    "Max fragment length: DTLS client, larger message" \
             "$P_SRV debug_level=3 dtls=1" \