diff --git a/extras/tests/Helpers/progmem_emulation.hpp b/extras/tests/Helpers/progmem_emulation.hpp
index ef309d10..f3c9246c 100644
--- a/extras/tests/Helpers/progmem_emulation.hpp
+++ b/extras/tests/Helpers/progmem_emulation.hpp
@@ -24,6 +24,11 @@ inline uint8_t pgm_read_byte(const void* p) {
   return *reinterpret_cast<const uint8_t*>(convertFlashToPtr(p));
 }
 
-inline const void* pgm_read_ptr(const void* p) {
-  return *reinterpret_cast<const void* const*>(convertFlashToPtr(p));
+inline void* pgm_read_ptr(const void* p) {
+  return *reinterpret_cast<void* const*>(convertFlashToPtr(p));
 }
+
+#define ARDUINOJSON_DEFINE_PROGMEM_ARRAY(type, name, value)        \
+  static type const ARDUINOJSON_CONCAT2(name, _progmem)[] = value; \
+  static type const* name = reinterpret_cast<type const*>(         \
+      convertPtrToFlash(ARDUINOJSON_CONCAT2(name, _progmem)));
diff --git a/extras/tests/MixedConfiguration/enable_progmem_1.cpp b/extras/tests/MixedConfiguration/enable_progmem_1.cpp
index b862b419..a1d4249e 100644
--- a/extras/tests/MixedConfiguration/enable_progmem_1.cpp
+++ b/extras/tests/MixedConfiguration/enable_progmem_1.cpp
@@ -165,3 +165,22 @@ TEST_CASE("Reader<const __FlashStringHelper*>") {
     REQUIRE(buffer[6] == 'g');
   }
 }
+
+static void testStringification(DeserializationError error,
+                                std::string expected) {
+  const __FlashStringHelper* s = error.f_str();
+  CHECK(reinterpret_cast<const char*>(convertFlashToPtr(s)) == expected);
+}
+
+#define TEST_STRINGIFICATION(symbol) \
+  testStringification(DeserializationError::symbol, #symbol)
+
+TEST_CASE("DeserializationError::f_str()") {
+  TEST_STRINGIFICATION(Ok);
+  TEST_STRINGIFICATION(EmptyInput);
+  TEST_STRINGIFICATION(IncompleteInput);
+  TEST_STRINGIFICATION(InvalidInput);
+  TEST_STRINGIFICATION(NoMemory);
+  TEST_STRINGIFICATION(NotSupported);
+  TEST_STRINGIFICATION(TooDeep);
+}
diff --git a/src/ArduinoJson/Deserialization/DeserializationError.hpp b/src/ArduinoJson/Deserialization/DeserializationError.hpp
index f3f8a229..0c3c9423 100644
--- a/src/ArduinoJson/Deserialization/DeserializationError.hpp
+++ b/src/ArduinoJson/Deserialization/DeserializationError.hpp
@@ -86,18 +86,20 @@ class DeserializationError {
     return messages[_code];
   }
 
+#define ARDUINOJSON_EXPAND7(a, b, c, d, e, f, g) a, b, c, d, e, f, g
+
 #if ARDUINOJSON_ENABLE_PROGMEM
   const __FlashStringHelper* f_str() const {
-    static const char s0[] PROGMEM = "Ok";
-    static const char s1[] PROGMEM = "EmptyInput";
-    static const char s2[] PROGMEM = "IncompleteInput";
-    static const char s3[] PROGMEM = "InvalidInput";
-    static const char s4[] PROGMEM = "NoMemory";
-    static const char s5[] PROGMEM = "NotSupported";
-    static const char s6[] PROGMEM = "TooDeep";
-    static const char* const messages[] PROGMEM = {s0, s1, s2, s3, s4, s5, s6};
-    ARDUINOJSON_ASSERT(static_cast<size_t>(_code) <
-                       sizeof(messages) / sizeof(messages[0]));
+    ARDUINOJSON_DEFINE_PROGMEM_ARRAY(char, s0, "Ok");
+    ARDUINOJSON_DEFINE_PROGMEM_ARRAY(char, s1, "EmptyInput");
+    ARDUINOJSON_DEFINE_PROGMEM_ARRAY(char, s2, "IncompleteInput");
+    ARDUINOJSON_DEFINE_PROGMEM_ARRAY(char, s3, "InvalidInput");
+    ARDUINOJSON_DEFINE_PROGMEM_ARRAY(char, s4, "NoMemory");
+    ARDUINOJSON_DEFINE_PROGMEM_ARRAY(char, s5, "NotSupported");
+    ARDUINOJSON_DEFINE_PROGMEM_ARRAY(char, s6, "TooDeep");
+    ARDUINOJSON_DEFINE_PROGMEM_ARRAY(
+        const char*, messages,
+        ARDUINOJSON_EXPAND7({s0, s1, s2, s3, s4, s5, s6}));
     return reinterpret_cast<const __FlashStringHelper*>(
         pgm_read_ptr(messages + _code));
   }
diff --git a/src/ArduinoJson/Polyfills/pgmspace.hpp b/src/ArduinoJson/Polyfills/pgmspace.hpp
index ffeffd18..8c1b5ac6 100644
--- a/src/ArduinoJson/Polyfills/pgmspace.hpp
+++ b/src/ArduinoJson/Polyfills/pgmspace.hpp
@@ -76,3 +76,13 @@ inline void* memcpy_P(void* dst, ARDUINOJSON_NAMESPACE::pgm_p src, size_t n) {
   return dst;
 }
 #endif
+
+#ifndef ARDUINOJSON_DEFINE_PROGMEM_ARRAY
+#ifdef PROGMEM
+#define ARDUINOJSON_DEFINE_PROGMEM_ARRAY(type, name, value) \
+  static type const name[] PROGMEM = value;
+#else
+#define ARDUINOJSON_DEFINE_PROGMEM_ARRAY(type, name, value) \
+  static type const name[] = value;
+#endif
+#endif