diff --git a/CHANGES b/CHANGES
index 58f4109ec..2e2c72a2d 100644
--- a/CHANGES
+++ b/CHANGES
@@ -29,6 +29,7 @@ Bugfixes:
  - GB, GBA Savedata: Fix savestate-related save overwriting (fixes mgba.io/i/834)
  - Qt: Fix timezone issues with time overrides
  - Qt: Fix sprite export pausing game indefinitely (fixes mgba.io/i/841)
+ - ARM: Fix MSR when T bit is set
 Misc:
  - GBA Timer: Use global cycles for timers
  - GBA: Extend oddly-sized ROMs to full address space (fixes mgba.io/i/722)
diff --git a/src/arm/isa-arm.c b/src/arm/isa-arm.c
index 8533833bc..84e894313 100644
--- a/src/arm/isa-arm.c
+++ b/src/arm/isa-arm.c
@@ -663,8 +663,9 @@ DEFINE_INSTRUCTION_ARM(MSR,
 	}
 	_ARMReadCPSR(cpu);
 	if (cpu->executionMode == MODE_THUMB) {
-		LOAD_16(cpu->prefetch[0], (cpu->gprs[ARM_PC] - WORD_SIZE_THUMB) & cpu->memory.activeMask, cpu->memory.activeRegion);
-		LOAD_16(cpu->prefetch[1], cpu->gprs[ARM_PC] & cpu->memory.activeMask, cpu->memory.activeRegion);
+		cpu->prefetch[0] = 0x46C0; // nop
+		cpu->prefetch[1] &= 0xFFFF;
+		cpu->gprs[ARM_PC] += WORD_SIZE_THUMB;
 	} else {
 		LOAD_32(cpu->prefetch[0], (cpu->gprs[ARM_PC] - WORD_SIZE_ARM) & cpu->memory.activeMask, cpu->memory.activeRegion);
 		LOAD_32(cpu->prefetch[1], cpu->gprs[ARM_PC] & cpu->memory.activeMask, cpu->memory.activeRegion);
@@ -704,8 +705,9 @@ DEFINE_INSTRUCTION_ARM(MSRI,
 	}
 	_ARMReadCPSR(cpu);
 	if (cpu->executionMode == MODE_THUMB) {
-		LOAD_16(cpu->prefetch[0], (cpu->gprs[ARM_PC] - WORD_SIZE_THUMB) & cpu->memory.activeMask, cpu->memory.activeRegion);
-		LOAD_16(cpu->prefetch[1], cpu->gprs[ARM_PC] & cpu->memory.activeMask, cpu->memory.activeRegion);
+		cpu->prefetch[0] = 0x46C0; // nop
+		cpu->prefetch[1] &= 0xFFFF;
+		cpu->gprs[ARM_PC] += WORD_SIZE_THUMB;
 	} else {
 		LOAD_32(cpu->prefetch[0], (cpu->gprs[ARM_PC] - WORD_SIZE_ARM) & cpu->memory.activeMask, cpu->memory.activeRegion);
 		LOAD_32(cpu->prefetch[1], cpu->gprs[ARM_PC] & cpu->memory.activeMask, cpu->memory.activeRegion);