diff --git a/boot/Kconfig b/boot/Kconfig
index a212f262274..11175fb7bb2 100644
--- a/boot/Kconfig
+++ b/boot/Kconfig
@@ -734,6 +734,10 @@ config LEGACY_IMAGE_FORMAT
 config MEASURED_BOOT
 	bool "Measure boot images and configuration when booting without EFI"
 	depends on HASH && TPM_V2
+	select SHA1
+	select SHA256
+	select SHA384
+	select SHA512
 	help
 	  This option enables measurement of the boot process when booting
 	  without UEFI . Measurement involves creating cryptographic hashes
diff --git a/include/tpm-v2.h b/include/tpm-v2.h
index aedf2c0f4f5..4fd19c52fd7 100644
--- a/include/tpm-v2.h
+++ b/include/tpm-v2.h
@@ -278,48 +278,40 @@ struct digest_info {
 #define TCG2_BOOT_HASH_ALG_SM3_256 0x00000010
 
 static const struct digest_info hash_algo_list[] = {
+#if IS_ENABLED(CONFIG_SHA1)
 	{
 		"sha1",
 		TPM2_ALG_SHA1,
 		TCG2_BOOT_HASH_ALG_SHA1,
 		TPM2_SHA1_DIGEST_SIZE,
 	},
+#endif
+#if IS_ENABLED(CONFIG_SHA256)
 	{
 		"sha256",
 		TPM2_ALG_SHA256,
 		TCG2_BOOT_HASH_ALG_SHA256,
 		TPM2_SHA256_DIGEST_SIZE,
 	},
+#endif
+#if IS_ENABLED(CONFIG_SHA384)
 	{
 		"sha384",
 		TPM2_ALG_SHA384,
 		TCG2_BOOT_HASH_ALG_SHA384,
 		TPM2_SHA384_DIGEST_SIZE,
 	},
+#endif
+#if IS_ENABLED(CONFIG_SHA512)
 	{
 		"sha512",
 		TPM2_ALG_SHA512,
 		TCG2_BOOT_HASH_ALG_SHA512,
 		TPM2_SHA512_DIGEST_SIZE,
 	},
+#endif
 };
 
-static inline u16 tpm2_algorithm_to_len(enum tpm2_algorithms a)
-{
-	switch (a) {
-	case TPM2_ALG_SHA1:
-		return TPM2_SHA1_DIGEST_SIZE;
-	case TPM2_ALG_SHA256:
-		return TPM2_SHA256_DIGEST_SIZE;
-	case TPM2_ALG_SHA384:
-		return TPM2_SHA384_DIGEST_SIZE;
-	case TPM2_ALG_SHA512:
-		return TPM2_SHA512_DIGEST_SIZE;
-	default:
-		return 0;
-	}
-}
-
 /* NV index attributes */
 enum tpm_index_attrs {
 	TPMA_NV_PPWRITE		= 1UL << 0,
@@ -712,6 +704,41 @@ enum tpm2_algorithms tpm2_name_to_algorithm(const char *name);
  */
 const char *tpm2_algorithm_name(enum tpm2_algorithms);
 
+/**
+ * tpm2_algorithm_to_len() - Return an algorithm length for supported algorithm id
+ *
+ * @algorithm_id: algorithm defined in enum tpm2_algorithms
+ * Return: len or 0 if not supported
+ */
+u16 tpm2_algorithm_to_len(enum tpm2_algorithms algo);
+
+/*
+ * When measured boot is enabled via EFI or bootX commands all the algorithms
+ * above are selected by our Kconfigs. Due to U-Boots nature of being small there
+ * are cases where we need some functionality from the TPM -- e.g storage or RNG
+ * but we don't want to support measurements.
+ *
+ * The choice of hash algorithms are determined by the platform and the TPM
+ * configuration. Failing to cap a PCR in a bank which the platform left
+ * active is a security vulnerability. It permits the unsealing of secrets
+ * if an attacker can replay a good set of measurements into an unused bank.
+ *
+ * On top of that a previous stage bootloader (e.g TF-A), migh pass an eventlog
+ * since it doesn't have a TPM driver, which U-Boot needs to replace. The algorit h
+ * choice is a compile time option in that case and we need to make sure we conform.
+ *
+ * Add a variable here that sums the supported algorithms U-Boot was compiled
+ * with so we can refuse to do measurements if we don't support all of them
+ */
+
+/**
+ * tpm2_allow_extend() - Check if extending PCRs is allowed and safe
+ *
+ * @dev: TPM device
+ * Return: true if allowed
+ */
+bool tpm2_allow_extend(struct udevice *dev);
+
 /**
  * tpm2_is_active_pcr() - check the pcr_select. If at least one of the PCRs
  *			  supports the algorithm add it on the active ones
diff --git a/lib/Kconfig b/lib/Kconfig
index 189e6eb31aa..b3baa4b85b0 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -439,9 +439,6 @@ config TPM
 	depends on DM
 	imply DM_RNG
 	select SHA1
-	select SHA256
-	select SHA384
-	select SHA512
 	help
 	  This enables support for TPMs which can be used to provide security
 	  features for your board. The TPM can be connected via LPC or I2C
@@ -449,6 +446,9 @@ config TPM
 	  command to interactive the TPM. Driver model support is provided
 	  for the low-level TPM interface, but only one TPM is supported at
 	  a time by the TPM library.
+	  For size reasons only SHA1 is selected which is supported on TPM1.2.
+	  If you want a fully functional TPM enable all hashing algorithms.
+	  If you enabled measured boot all hashing algorithms are selected.
 
 config SPL_TPM
 	bool "Trusted Platform Module (TPM) Support in SPL"
diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c
index 36aace03cf4..59e6cbafafa 100644
--- a/lib/tpm-v2.c
+++ b/lib/tpm-v2.c
@@ -196,6 +196,11 @@ u32 tpm2_pcr_extend(struct udevice *dev, u32 index, u32 algorithm,
 
 	if (!digest)
 		return -EINVAL;
+
+	if (!tpm2_allow_extend(dev)) {
+		log_err("Cannot extend PCRs if all the TPM enabled algorithms are not supported\n");
+		return -EINVAL;
+	}
 	/*
 	 * Fill the command structure starting from the first buffer:
 	 *     - the digest
@@ -409,11 +414,10 @@ int tpm2_get_pcr_info(struct udevice *dev, struct tpml_pcr_selection *pcrs)
 
 	pcrs->count = get_unaligned_be32(response);
 	/*
-	 * We only support 5 algorithms for now so check against that
+	 * We only support 4 algorithms for now so check against that
 	 * instead of TPM2_NUM_PCR_BANKS
 	 */
-	if (pcrs->count > ARRAY_SIZE(hash_algo_list) ||
-	    pcrs->count < 1) {
+	if (pcrs->count > 4 || pcrs->count < 1) {
 		printf("%s: too many pcrs: %u\n", __func__, pcrs->count);
 		return -EMSGSIZE;
 	}
@@ -880,3 +884,33 @@ const char *tpm2_algorithm_name(enum tpm2_algorithms algo)
 	return "";
 }
 
+u16 tpm2_algorithm_to_len(enum tpm2_algorithms algo)
+{
+	size_t i;
+
+	for (i = 0; i < ARRAY_SIZE(hash_algo_list); ++i) {
+		if (hash_algo_list[i].hash_alg == algo)
+			return hash_algo_list[i].hash_len;
+	}
+
+	return 0;
+}
+
+bool tpm2_allow_extend(struct udevice *dev)
+{
+	struct tpml_pcr_selection pcrs;
+	size_t i;
+	int rc;
+
+	rc = tpm2_get_pcr_info(dev, &pcrs);
+	if (rc)
+		return false;
+
+	for (i = 0; i < pcrs.count; i++) {
+		if (tpm2_is_active_pcr(&pcrs.selection[i]) &&
+		    !tpm2_algorithm_to_len(pcrs.selection[i].hash))
+			return false;
+	}
+
+	return true;
+}