diff --git a/uc.c b/uc.c
index f69cf3a7..965d772a 100644
--- a/uc.c
+++ b/uc.c
@@ -754,12 +754,13 @@ uc_err uc_emu_start(uc_engine *uc, uint64_t begin, uint64_t until,
     }
     uc->nested_level++;
 
+    uint32_t begin_pc32 = READ_DWORD(begin);
     switch (uc->arch) {
     default:
         break;
 #ifdef UNICORN_HAS_M68K
     case UC_ARCH_M68K:
-        uc_reg_write(uc, UC_M68K_REG_PC, &begin);
+        uc_reg_write(uc, UC_M68K_REG_PC, &begin_pc32);
         break;
 #endif
 #ifdef UNICORN_HAS_X86
@@ -778,7 +779,7 @@ uc_err uc_emu_start(uc_engine *uc, uint64_t begin, uint64_t until,
             break;
         }
         case UC_MODE_32:
-            uc_reg_write(uc, UC_X86_REG_EIP, &begin);
+            uc_reg_write(uc, UC_X86_REG_EIP, &begin_pc32);
             break;
         case UC_MODE_64:
             uc_reg_write(uc, UC_X86_REG_RIP, &begin);
@@ -788,7 +789,7 @@ uc_err uc_emu_start(uc_engine *uc, uint64_t begin, uint64_t until,
 #endif
 #ifdef UNICORN_HAS_ARM
     case UC_ARCH_ARM:
-        uc_reg_write(uc, UC_ARM_REG_R15, &begin);
+        uc_reg_write(uc, UC_ARM_REG_R15, &begin_pc32);
         break;
 #endif
 #ifdef UNICORN_HAS_ARM64
@@ -799,7 +800,7 @@ uc_err uc_emu_start(uc_engine *uc, uint64_t begin, uint64_t until,
 #ifdef UNICORN_HAS_MIPS
     case UC_ARCH_MIPS:
         // TODO: MIPS32/MIPS64/BIGENDIAN etc
-        uc_reg_write(uc, UC_MIPS_REG_PC, &begin);
+        uc_reg_write(uc, UC_MIPS_REG_PC, &begin_pc32);
         break;
 #endif
 #ifdef UNICORN_HAS_SPARC
@@ -815,7 +816,11 @@ uc_err uc_emu_start(uc_engine *uc, uint64_t begin, uint64_t until,
 #endif
 #ifdef UNICORN_HAS_RISCV
     case UC_ARCH_RISCV:
-        uc_reg_write(uc, UC_RISCV_REG_PC, &begin);
+        if (uc->mode & UC_MODE_RISCV64) {
+            uc_reg_write(uc, UC_RISCV_REG_PC, &begin);
+        } else {
+            uc_reg_write(uc, UC_RISCV_REG_PC, &begin_pc32);
+        }
         break;
 #endif
 #ifdef UNICORN_HAS_S390X
@@ -825,7 +830,7 @@ uc_err uc_emu_start(uc_engine *uc, uint64_t begin, uint64_t until,
 #endif
 #ifdef UNICORN_HAS_TRICORE
     case UC_ARCH_TRICORE:
-        uc_reg_write(uc, UC_TRICORE_REG_PC, &begin);
+        uc_reg_write(uc, UC_TRICORE_REG_PC, &begin_pc32);
         break;
 #endif
     }