diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 766a9b91e3c0a..856a88bdc3aad 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -844,6 +844,16 @@ static bool UseRelaxAll(Compilation &C, const ArgList &Args) {
   if (Arg *A = Args.getLastArg(options::OPT_O_Group))
     RelaxDefault = A->getOption().matches(options::OPT_O0);
 
+  // RISC-V requires an indirect jump for offsets larger than 1MiB. This cannot
+  // be done by assembler branch relaxation as it needs a free temporary
+  // register. Because of this, branch relaxation is handled by a MachineIR
+  // pass before the assembler. Forcing assembler branch relaxation for -O0
+  // makes the MachineIR branch relaxation inaccurate and it will miss cases
+  // where an indirect branch is necessary. To avoid this issue we are
+  // sacrificing the compile time improvement of using -mrelax-all for -O0.
+  if (C.getDefaultToolChain().getTriple().isRISCV())
+    RelaxDefault = false;
+
   if (RelaxDefault) {
     RelaxDefault = false;
     for (const auto &Act : C.getActions()) {
diff --git a/clang/test/Driver/integrated-as.c b/clang/test/Driver/integrated-as.c
index d7658fdfd6337..e78fde873cf47 100644
--- a/clang/test/Driver/integrated-as.c
+++ b/clang/test/Driver/integrated-as.c
@@ -1,10 +1,16 @@
 // XFAIL: target={{.*}}-aix{{.*}}
 
-// RUN: %clang -### -c -save-temps -integrated-as %s 2>&1 | FileCheck %s
+// RUN: %clang -### -c -save-temps -integrated-as --target=x86_64 %s 2>&1 | FileCheck %s
 
 // CHECK: cc1as
 // CHECK: -mrelax-all
 
+// RISC-V does not enable -mrelax-all
+// RUN: %clang -### -c -save-temps -integrated-as --target=riscv64 %s 2>&1 | FileCheck %s -check-prefix=RISCV-RELAX
+
+// RISCV-RELAX: cc1as
+// RISCV-RELAX-NOT: -mrelax-all
+
 // RUN: %clang -### -fintegrated-as -c -save-temps %s 2>&1 | FileCheck %s -check-prefix FIAS
 
 // FIAS: cc1as