diff --git a/lib/libmbedtls/mbedtls/library/bignum.c b/lib/libmbedtls/mbedtls/library/bignum.c
index 107a397..7b8b966 100644
--- a/lib/libmbedtls/mbedtls/library/bignum.c
+++ b/lib/libmbedtls/mbedtls/library/bignum.c
@@ -1846,7 +1846,7 @@
                         mbedtls_mpi *prec_RR)
 {
 #if (defined(__KERNEL__) && defined(CFG_CORE_UNSAFE_MODEXP)) || \
-    (!defined(__KERNEL__) && defined(CFG_TA_MEBDTLS_UNSAFE_MODEXP))
+    (!defined(__KERNEL__) && defined(CFG_TA_MBEDTLS_UNSAFE_MODEXP))
     return mbedtls_mpi_exp_mod_unsafe(X, A, E, N, prec_RR);
 #else
     return mbedtls_mpi_exp_mod_optionally_safe(X, A, E, MBEDTLS_MPI_IS_SECRET, N, prec_RR);
diff --git a/mk/config.mk b/mk/config.mk
index 8524bb9..cc832ba 100644
--- a/mk/config.mk
+++ b/mk/config.mk
@@ -1262,7 +1262,7 @@
 # CFG_TA_MBEDTLS_UNSAFE_MODEXP, similar to CFG_CORE_UNSAFE_MODEXP,
 # when enabled, makes MBedTLS library for TAs use 'unsafe' modular
 # exponentiation algorithm.
-CFG_TA_MEBDTLS_UNSAFE_MODEXP ?= n
+CFG_TA_MBEDTLS_UNSAFE_MODEXP ?= n
 
 # CFG_BOOT_INIT_THREAD_CORE_LOCAL0, when enabled, initializes
 # thread_core_local[0] before calling C code.