diff --git a/src/p_lx_elf.cpp b/src/p_lx_elf.cpp
index 7bee5828..fc2d0d91 100644
--- a/src/p_lx_elf.cpp
+++ b/src/p_lx_elf.cpp
@@ -212,6 +212,12 @@ PackLinuxElf32::PackLinuxElf32help1(InputFile *f)
     e_type  = get_te16(&ehdri.e_type);
     e_phnum = get_te16(&ehdri.e_phnum);
     e_shnum = get_te16(&ehdri.e_shnum);
+    if (ehdri.e_ident[Elf32_Ehdr::EI_CLASS]!=Elf32_Ehdr::ELFCLASS32) {
+        e_phoff = 0;
+        e_shoff = 0;
+        sz_phdrs = 0;
+        return;
+    }
     e_phoff = get_te32(&ehdri.e_phoff);
     e_shoff = get_te32(&ehdri.e_shoff);
     sz_phdrs = e_phnum * get_te16(&ehdri.e_phentsize);
@@ -567,6 +573,12 @@ PackLinuxElf64::PackLinuxElf64help1(InputFile *f)
     e_type  = get_te16(&ehdri.e_type);
     e_phnum = get_te16(&ehdri.e_phnum);
     e_shnum = get_te16(&ehdri.e_shnum);
+    if (ehdri.e_ident[Elf64_Ehdr::EI_CLASS]!=Elf64_Ehdr::ELFCLASS64) {
+        e_phoff = 0;
+        e_shoff = 0;
+        sz_phdrs = 0;
+        return;
+    }
     e_phoff = get_te64(&ehdri.e_phoff);
     e_shoff = get_te64(&ehdri.e_shoff);
     sz_phdrs = e_phnum * get_te16(&ehdri.e_phentsize);
diff --git a/src/p_lx_elf.h b/src/p_lx_elf.h
index 03bc575a..b22d5ca7 100644
--- a/src/p_lx_elf.h
+++ b/src/p_lx_elf.h
@@ -72,8 +72,6 @@ protected:
     unsigned e_type;
     unsigned e_phnum;       /* Program header table entry count */
     unsigned e_shnum;
-    unsigned e_phoff;
-    unsigned e_shoff;
     char       *file_image;       // if ET_DYN investigation
     char const *dynstr;   // from DT_STRTAB
 
@@ -153,6 +151,8 @@ protected:
 protected:
     Elf32_Ehdr  ehdri; // from input file
     Elf32_Phdr *phdri; // for  input file
+    unsigned e_phoff;
+    unsigned e_shoff;
     unsigned char *note_body;  // concatenated contents of PT_NOTEs, if any
     unsigned note_size;  // total size of PT_NOTEs
     Elf32_Shdr const *shdri; // from input file
@@ -268,6 +268,8 @@ protected:
 protected:
     Elf64_Ehdr  ehdri; // from input file
     Elf64_Phdr *phdri; // for  input file
+    upx_uint64_t e_phoff;
+    upx_uint64_t e_shoff;
     unsigned char *note_body;  // concatenated contents of PT_NOTEs, if any
     unsigned note_size;  // total size of PT_NOTEs
     Elf64_Shdr const *shdri; // from input file