diff --git a/include/mbedtls/pk.h b/include/mbedtls/pk.h
index 09a8513..b6c2998 100644
--- a/include/mbedtls/pk.h
+++ b/include/mbedtls/pk.h
@@ -49,6 +49,10 @@
 #include "tinycrypt/ecc.h"
 #endif
 
+#if defined(MBEDTLS_PK_SINGLE_TYPE)
+#include "pk_internal.h"
+#endif
+
 #if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
     !defined(inline) && !defined(__cplusplus)
 #define inline __inline
@@ -137,17 +141,6 @@
 #define MBEDTLS_PK_INVALID_HANDLE ( (mbedtls_pk_handle_t) NULL )
 #endif /* MBEDTLS_PK_SINGLE_TYPE */
 
-/**
- * \brief           Public key container
- */
-typedef struct mbedtls_pk_context
-{
-#if !defined(MBEDTLS_PK_SINGLE_TYPE)
-    mbedtls_pk_handle_t         pk_info; /**< Public key information         */
-#endif
-    void *                      pk_ctx;  /**< Underlying public key context  */
-} mbedtls_pk_context;
-
 #if defined(MBEDTLS_USE_TINYCRYPT)
 typedef struct
 {
@@ -156,6 +149,22 @@
 } mbedtls_uecc_keypair;
 #endif
 
+/**
+ * \brief           Public key container
+ */
+typedef struct mbedtls_pk_context
+{
+#if defined(MBEDTLS_PK_SINGLE_TYPE)
+    /* This is an array to make access to it more uniform with the case where
+     * it's a pointer to void - either way it needs casting before use. */
+    unsigned char pk_ctx[sizeof(
+                         MBEDTLS_PK_INFO_CONTEXT( MBEDTLS_PK_SINGLE_TYPE ) )];
+#else
+    mbedtls_pk_handle_t         pk_info; /**< Public key information         */
+    void *                      pk_ctx;  /**< Underlying public key context  */
+#endif
+} mbedtls_pk_context;
+
 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
 /**
  * \brief           Context for resuming operations
@@ -184,11 +193,18 @@
 #endif /* MBEDTLS_RSA_C */
 
 #if defined(MBEDTLS_USE_TINYCRYPT)
+#if !defined(MBEDTLS_PK_SINGLE_TYPE)
 static inline mbedtls_uecc_keypair *mbedtls_pk_uecc( const mbedtls_pk_context pk )
 {
     return( (mbedtls_uecc_keypair *) (pk).pk_ctx );
 }
+#else
+/* Go with a macro in order to avoid making a copy of the struct (the argument
+ * is not a pointer so it's passed by value) and then returning an address
+ * inside that copy, which would be undefined behaviour. */
+#define mbedtls_pk_uecc( pk )   ( (mbedtls_uecc_keypair *) (pk).pk_ctx )
 #endif
+#endif /* MBEDTLS_USE_TINYCRYPT */
 
 #if defined(MBEDTLS_ECP_C)
 /**